using System;
using System.ComponentModel;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.Contracts;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Runtime.Intrinsics.X86;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
using static Functions;
using static OutputLib;

using ModInt = StaticModInt<Mod998244353>;

static class Program
{
    static public void Main(string[] args)
    {
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver();
        Console.Out.Flush();
    }
}

public class Solver
{
    public Solver()
    {
        Solve();
    }

    void Solve()
    {
        int d = ri, q = ri;
        var set = new IntervalSet();
        var ans = new List<long>();
        long max = 0;
        for (int i = 0; i < q; i++)
        {
            long a = rl, b = rl;
            set.Add(a, b, true);
            var p = set.Get(a);
            Chmax(ref max, p.r - p.l + 1);
            ans.Add(max);
        }
        WriteJoin("\n", ans);
    }

    const long INF = 1L << 60;
    int ri { [MethodImpl(256)] get => (int)sc.Integer(); }
    long rl { [MethodImpl(256)] get => sc.Integer(); }
    uint rui { [MethodImpl(256)] get => (uint)sc.UInteger(); }
    ulong rul { [MethodImpl(256)] get => sc.UInteger(); }
    double rd { [MethodImpl(256)] get => sc.Double(); }
    string rs { [MethodImpl(256)] get => sc.Scan(); }
    string rline { [MethodImpl(256)] get => sc.Line(); }
    public StreamScanner sc = new StreamScanner(Console.OpenStandardInput());
}

public static class Functions
{
    [MethodImpl(256)]
    public static int Popcount(ulong x)
    {
        x = (x & 0x5555555555555555UL) + ((x >> 1) & 0x5555555555555555UL);
        x = (x & 0x3333333333333333UL) + ((x >> 2) & 0x3333333333333333UL);
        x = (x & 0x0f0f0f0f0f0f0f0fUL) + ((x >> 4) & 0x0f0f0f0f0f0f0f0fUL);
        x = (x & 0x00ff00ff00ff00ffUL) + ((x >> 8) & 0x00ff00ff00ff00ffUL);
        x = (x & 0x0000ffff0000ffffUL) + ((x >> 16) & 0x0000ffff0000ffffUL);
        x = (x & 0x00000000ffffffffUL) + ((x >> 32) & 0x00000000ffffffffUL);
        return (int)x;
    }
    [MethodImpl(256)]
    public static int Popcount(int x)
    {
        x = (x & 0x55555555) + ((x >> 1) & 0x55555555);
        x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
        x = (x & 0x0f0f0f0f) + ((x >> 4) & 0x0f0f0f0f);
        x = (x & 0x00ff00ff) + ((x >> 8) & 0x00ff00ff);
        x = (x & 0x0000ffff) + ((x >> 16) & 0x0000ffff);
        return x;
    }
    [MethodImpl(256)]
    public static int Ctz(long x)
    {
        if (x == 0) return -1;
        return Popcount((ulong)((x & -x) - 1));
    }
    [MethodImpl(256)]
    public static int CeilPow2(int n)
    {
        int x = 0;
        while ((1 << x) < n) x++;
        return x;
    }
    [MethodImpl(256)]
    public static int SafeMod(int x, int m)
    {
        int r = x % m;
        return r < 0 ? r + Math.Abs(m) : r;
    }
    [MethodImpl(256)]
    public static long SafeMod(long x, long m)
    {
        long r = x % m;
        return r < 0 ? r + Math.Abs(m) : r;
    }
    [MethodImpl(256)] public static int Sign(long x) => x == 0 ? 0 : (x < 0 ? -1 : 1);
    [MethodImpl(256)] public static int Sign(double x) => x == 0 ? 0 : (x < 0 ? -1 : 1);
    [MethodImpl(256)] public static int DigitSum(long n, int d = 10) { long s = 0; while (n > 0) { s += n % d; n /= d; } return (int)s; }
    [MethodImpl(256)] public static long Floor(long a, long b) => a >= 0 ? a / b : (a + 1) / b - 1;
    [MethodImpl(256)] public static long Ceil(long a, long b) => a > 0 ? (a - 1) / b + 1 : a / b;
    [MethodImpl(256)] public static int Gcd(int a, int b) => b == 0 ? a : Gcd(b, a % b);
    [MethodImpl(256)] public static long Gcd(long a, long b) => b == 0 ? a : Gcd(b, a % b);
    [MethodImpl(256)] public static void Swap(ref int x, ref int y) { x ^= y; y ^= x; x ^= y; }
    [MethodImpl(256)] public static void Swap(ref long x, ref long y) { x ^= y; y ^= x; x ^= y; }
    [MethodImpl(256)] public static void Swap<T>(ref T x, ref T y) { T t = y; y = x; x = t; }
    [MethodImpl(256)] public static T Clamp<T>(T x, T l, T r) where T : IComparable<T> => x.CompareTo(l) <= 0 ? l : (x.CompareTo(r) <= 0 ? x : r);
    [MethodImpl(256)] public static T Clamp<T>(ref T x, T l, T r) where T : IComparable<T> => x = x.CompareTo(l) <= 0 ? l : (x.CompareTo(r) <= 0 ? x : r);
    [MethodImpl(256)] public static void Chmin<T>(ref T x, T y) where T : IComparable<T> { if (x.CompareTo(y) > 0) x = y; }
    [MethodImpl(256)] public static void Chmax<T>(ref T x, T y) where T : IComparable<T> { if (x.CompareTo(y) < 0) x = y; }
    public static int LowerBound(long[] arr, long val, int l = -1, int r = -1) => LowerBound<long>(arr.AsSpan(), t => Sign(t - val), l, r);
    public static int LowerBound(int[] arr, int val, int l = -1, int r = -1) => LowerBound<int>(arr.AsSpan(), t => t - val, l, r);
    public static int LowerBound<T>(T[] arr, Func<T, int> comp, int l = -1, int r = -1) => LowerBound<T>(arr.AsSpan<T>(), comp, l, r);
    public static int LowerBound<T>(Span<T> data, Func<T, int> comp, int l = -1, int r = -1)
    {
        if (data.Length == 0) return -1;
        if (l == -1) l = 0;
        if (r == -1) r = data.Length;
        while (l < r)
        {
            int x = (l + r) / 2;
            if (comp(data[x]) < 0) l = x + 1;
            else r = x;
        }
        return l;
    }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static string ToBase2(long v, int digit = -1)
    {
        if (digit == -1)
        {
            digit = 0;
            while ((v >> digit) > 0) digit++;
        }
        var c = new string[digit];
        for (int i = 0; i < digit; i++) c[digit - 1 - i] = ((v >> i) & 1) == 0 ? "0" : "1";
        return string.Join("", c);
    }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static string ToBaseN(long v, int n, int digit = -1)
    {
        if (digit == -1)
        {
            digit = 0;
            long pow = 1;
            while (v >= pow) { digit++; pow *= n; }
        }
        var c = new int[digit];
        for (int i = 0; i < digit; i++, v /= n) c[digit - 1 - i] = (int)(v % n);
        return string.Join("", c);
    }
}

public class StreamScanner
{
    public StreamScanner(Stream stream) { str = stream; }
    private readonly Stream str;
    private readonly byte[] buf = new byte[1024];
    private int len, ptr;
    public bool isEof = false;
    public bool IsEndOfStream { get { return isEof; } }
    [MethodImpl(256)]
    private byte read()
    {
        if (isEof) throw new EndOfStreamException();
        if (ptr >= len)
        {
            ptr = 0;
            if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; }
        }
        return buf[ptr++];
    }
    [MethodImpl(256)]
    public char Char()
    {
        byte b = 0;
        do b = read();
        while (b < 33 || 126 < b);
        return (char)b;
    }
    [MethodImpl(256)]
    public string Line()
    {
        var sb = new StringBuilder();
        for (var b = Char(); b != 10 && !isEof; b = (char)read()) sb.Append(b);
        return sb.ToString();
    }
    [MethodImpl(256)]
    public string Scan()
    {
        var sb = new StringBuilder();
        for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b);
        return sb.ToString();
    }
    [MethodImpl(256)]
    public long Integer()
    {
        long ret = 0; byte b = 0; var ng = false;
        do b = read();
        while (b != '-' && (b < '0' || '9' < b));
        if (b == '-') { ng = true; b = read(); }
        for (; true; b = read())
        {
            if (b < '0' || '9' < b) return ng ? -ret : ret;
            else ret = ret * 10 + b - '0';
        }
    }
    [MethodImpl(256)]
    public ulong UInteger()
    {
        ulong ret = 0; byte b = 0;
        do b = read();
        while (b < '0' || '9' < b);
        for (; true; b = read())
        {
            if (b < '0' || '9' < b) return ret;
            else ret = ret * 10 + b - '0';
        }
    }
    [MethodImpl(256)]
    public double Double() => double.Parse(Scan());
}

public static class OutputLib
{
    [MethodImpl(256)] public static void WriteJoin<T>(string s, IEnumerable<T> t) => Console.WriteLine(string.Join(s, t));
    [MethodImpl(256)]
    public static void WriteMat<T>(T[,] a)
    {
        int sz1 = a.GetLength(0);
        int sz2 = a.GetLength(1);
        for (int i = 0; i < sz1; i++)
        {
            var b = new T[sz2];
            for (int j = 0; j < sz2; j++) b[j] = a[i, j];
            WriteJoin(" ", b);
        }
    }
    [MethodImpl(256)] public static void WriteMat<T>(T[][] a) { for (int i = 0; i < a.Length; i++) WriteJoin(" ", a[i]); }
    [MethodImpl(256)] public static void Write(object t) => Console.WriteLine(t.ToString());
    [MethodImpl(256)] public static void Write(string str) => Console.WriteLine(str);
    [MethodImpl(256)] public static void Write(string str, object arg1) => Console.WriteLine(str, arg1);
    [MethodImpl(256)] public static void Write(string str, object arg1, object arg2) => Console.WriteLine(str, arg1, arg2);
    [MethodImpl(256)] public static void Write(string str, object arg1, object arg2, object arg3) => Console.WriteLine(str, arg1, arg2, arg3);
    [MethodImpl(256)] public static void Write(string str, params object[] arg) => Console.WriteLine(str, arg);
    [MethodImpl(256)] public static void WriteFlush(object t) { Console.WriteLine(t.ToString()); Console.Out.Flush(); }
    [MethodImpl(256)] public static void WriteError(object t) => Console.Error.WriteLine(t.ToString());
    [MethodImpl(256)] public static void Flush() => Console.Out.Flush();
    [MethodImpl(256)] public static void YN(bool t) => Console.WriteLine(t ? "YES" : "NO");
    [MethodImpl(256)] public static void Yn(bool t) => Console.WriteLine(t ? "Yes" : "No");
    [MethodImpl(256)] public static void yn(bool t) => Console.WriteLine(t ? "yes" : "no");
}

public interface IStaticMod
{
    uint Mod { get; }
    bool IsPrime { get; }
}
public readonly struct Mod1000000007 : IStaticMod
{
    public uint Mod => 1000000007;
    public bool IsPrime => true;
}
public readonly struct Mod998244353 : IStaticMod
{
    public uint Mod => 998244353;
    public bool IsPrime => true;
}
public readonly struct StaticModInt<T> : IEquatable<StaticModInt<T>>, IFormattable where T : struct, IStaticMod
{
    internal readonly uint _v;
    private static readonly T op = default;
    public int Value => (int)_v;
    public static int Mod => (int)op.Mod;
    public static StaticModInt<T> Zero => default;
    public static StaticModInt<T> One => new StaticModInt<T>(1u);
    [MethodImpl(256)]
    public static StaticModInt<T> Raw(int v)
    {
        var u = unchecked((uint)v);
        return new StaticModInt<T>(u);
    }
    [MethodImpl(256)]
    public StaticModInt(long v) : this(Round(v)) { }
    [MethodImpl(256)]
    public StaticModInt(ulong v) : this((uint)(v % op.Mod)) { }
    [MethodImpl(256)]
    private StaticModInt(uint v) => _v = v;
    [MethodImpl(256)]
    private static uint Round(long v)
    {
        var x = v % op.Mod;
        if (x < 0) x += op.Mod;
        return (uint)x;
    }
    [MethodImpl(256)]
    public static StaticModInt<T> operator ++(StaticModInt<T> v)
    {
        var x = v._v + 1;
        if (x == op.Mod) x = 0;
        return new StaticModInt<T>(x);
    }
    [MethodImpl(256)]
    public static StaticModInt<T> operator --(StaticModInt<T> v)
    {
        var x = v._v;
        if (x == 0) x = op.Mod;
        return new StaticModInt<T>(x - 1);
    }
    [MethodImpl(256)]
    public static StaticModInt<T> operator +(StaticModInt<T> lhs, StaticModInt<T> rhs)
    {
        var v = lhs._v + rhs._v;
        if (v >= op.Mod) v -= op.Mod;
        return new StaticModInt<T>(v);
    }
    [MethodImpl(256)]
    public static StaticModInt<T> operator -(StaticModInt<T> lhs, StaticModInt<T> rhs)
    {
        unchecked
        {
            var v = lhs._v - rhs._v;
            if (v >= op.Mod) v += op.Mod;
            return new StaticModInt<T>(v);
        }
    }
    [MethodImpl(256)]
    public static StaticModInt<T> operator *(StaticModInt<T> lhs, StaticModInt<T> rhs) => new StaticModInt<T>((uint)((ulong)lhs._v * rhs._v % op.Mod));
    [MethodImpl(256)]
    public static StaticModInt<T> operator /(StaticModInt<T> lhs, StaticModInt<T> rhs) => lhs * rhs.Inv();
    [MethodImpl(256)]
    public static StaticModInt<T> operator +(StaticModInt<T> v) => v;
    [MethodImpl(256)]
    public static StaticModInt<T> operator -(StaticModInt<T> v) => new StaticModInt<T>(v._v == 0 ? 0 : op.Mod - v._v);
    [MethodImpl(256)]
    public static bool operator ==(StaticModInt<T> lhs, StaticModInt<T> rhs) => lhs._v == rhs._v;
    [MethodImpl(256)]
    public static bool operator !=(StaticModInt<T> lhs, StaticModInt<T> rhs) => lhs._v != rhs._v;
    [MethodImpl(256)]
    public static implicit operator StaticModInt<T>(int v) => new StaticModInt<T>(v);
    [MethodImpl(256)]
    public static implicit operator StaticModInt<T>(uint v) => new StaticModInt<T>((long)v);
    [MethodImpl(256)]
    public static implicit operator StaticModInt<T>(long v) => new StaticModInt<T>(v);
    [MethodImpl(256)]
    public static implicit operator StaticModInt<T>(ulong v) => new StaticModInt<T>(v);
    [MethodImpl(256)]
    public static implicit operator long(StaticModInt<T> v) => v._v;
    [MethodImpl(256)]
    public static implicit operator ulong(StaticModInt<T> v) => v._v;
    [MethodImpl(256)]
    public StaticModInt<T> Pow(long n)
    {
        var x = this;
        var r = new StaticModInt<T>(1U);
        while (n > 0)
        {
            if ((n & 1) > 0) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    [MethodImpl(256)]
    public StaticModInt<T> Inv()
    {
        var (x, y, g) = ExtGcd(_v, op.Mod);
        return new StaticModInt<T>(x);
    }
    [MethodImpl(256)]
    static (long x, long y, long g) ExtGcd(long a, long b)
    {
        if (b == 0) return a >= 0 ? (1, 0, a) : (-1, 0, -a);
        long c = SafeMod(a, b);
        var (x2, y2, g) = ExtGcd(b, c);
        long x = SafeMod(y2, b);
        long y = (g - a * x) / b;
        return (x, y, g);
    }
    [MethodImpl(256)]
    static long SafeMod(long x, long m)
    {
        long r = x % m;
        if (r < 0) r += m;
        return r;
    }
    [MethodImpl(256)]
    public override string ToString() => _v.ToString();
    [MethodImpl(256)]
    public string ToString(string format, IFormatProvider formatProvider) => _v.ToString(format, formatProvider);
    [MethodImpl(256)]
    public override bool Equals(object obj) => obj is StaticModInt<T> m && Equals(m);
    [MethodImpl(256)]
    public bool Equals(StaticModInt<T> other) => _v == other._v;
    [MethodImpl(256)]
    public override int GetHashCode() => _v.GetHashCode();
}

public class IntervalSet
{
    readonly RedBlackTree<long, (long l, long r)> set;
    public IntervalSet()
    {
        set = new RedBlackTree<long, (long l, long r)>(x => x.l);
    }

    [MethodImpl(256)]
    public bool Contains(long x)
    {
        var idx = set.UpperBoundKey(x) - 1;
        return 0 <= idx && idx < set.Count() && x <= set[idx].r;
    }

    [MethodImpl(256)]
    public (long l, long r) Get(long x)
    {
        var idx = set.UpperBoundKey(x) - 1;
        if (0 <= idx && idx < set.Count())
        {
            var p = set[idx];
            if (x <= p.r) return p;
        }
        return (-1, -1);
    }

    [MethodImpl(256)]
    public List<(long l, long r)> Add(long l, long r, bool merge = false)
    {
        var ret = Remove(l, r);
        if (merge)
        {
            var idx = set.LowerBoundKey(l);
            if (idx < set.Count())
            {
                var p = set[idx];
                if (p.l == r + 1)
                {
                    set.RemoveAt(idx);
                    r = p.r;
                }
            }
            idx--;
            if (idx >= 0)
            {
                var p = set[idx];
                if (p.r == l - 1)
                {
                    set.RemoveAt(idx);
                    l = p.l;
                }
            }
        }
        set.Add((l, r));
        return ret;
    }

    [MethodImpl(256)]
    public List<(long l, long r)> Remove(long l, long r)
    {
        var idx = set.UpperBoundKey(l) - 1;
        if (0 <= idx && idx < set.Count())
        {
            var p = set[idx];
            if (p.r >= r)
            {
                set.RemoveAt(idx);
                if (p.l < l) set.Add((p.l, l - 1));
                if (r < p.r) set.Add((r + 1, p.r));
                return new List<(long l, long r)>() { (l, r) };
            }
        }
        var ret = new List<(long l, long r)>();
        idx = set.UpperBoundKey(r);
        while (true)
        {
            idx--;
            if (idx < 0 || idx >= set.Count()) break;
            var p = set[idx];
            if (p.l < l)
            {
                if (p.r >= l)
                {
                    ret.Add((l, p.r));
                    set.RemoveAt(idx);
                    if (p.l < l) set.Add((p.l, l - 1));
                }
                break;
            }
            ret.Add((p.l, Math.Min(p.r, r)));
            set.RemoveAt(idx);
            if (r < p.r) set.Add((r + 1, p.r));
        }
        return ret;
    }

    [MethodImpl(256)]
    public List<(long l, long r)> Get(long l, long r)
    {
        var idx = set.UpperBoundKey(l) - 1;
        if (0 <= idx && idx < set.Count())
        {
            var p = set[idx];
            if (p.r >= r)
                return new List<(long l, long r)>() { (l, r) };
        }
        var ret = new List<(long l, long r)>();
        idx = set.UpperBoundKey(r);
        while (l <= r)
        {
            idx--;
            if (idx < 0 || idx >= set.Count()) break;
            var p = set[idx];
            if (p.l < l)
            {
                if (p.r >= l) ret.Add((l, p.r));
                break;
            }
            ret.Add((p.l, Math.Min(p.r, r)));
            r = p.l - 1;
        }
        return ret;
    }
}

class RedBlackTree<TKey, TValue> : IEnumerable<TValue>
{
    private readonly Func<TValue, TKey> _keySelector;
    private readonly IComparer<TKey> _keyComparer;
    class Node
    {
        public Node Parent { get; set; }
        public Node LChild { get; set; }
        public Node RChild { get; set; }
        public int Color { get; set; }
        public long CountSum { get; set; }
        public long Count { get; set; }
        public TKey Key { get; }
        public TValue Value { get; }
        public void ReplaceChild(Node x, Node y = null)
        {
            if (LChild == x) LChild = y;
            if (RChild == x) RChild = y;
        }
        public Node(TKey _key, TValue _val, long _count, Node _par = null, int _color = 0)
        {
            Key = _key;
            Value = _val;
            Count = _count;
            CountSum = Count;
            Color = _color;
            Parent = _par;
            LChild = null;
            RChild = null;
        }
        public override string ToString() => $"[{Parent}]->{Value}*{Count}[{Color}]->[{LChild},{RChild}]:{CountSum}";
    }
    public IEnumerator<TValue> GetEnumerator() => ToList().GetEnumerator();
    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
    Node Root;
    public long CountAll { get; private set; }
    public RedBlackTree(Func<TValue, TKey> keySelector) : this(keySelector, Comparer<TKey>.Default) { }
    public RedBlackTree(Func<TValue, TKey> keySelector, IComparer<TKey> keyComparer)
    {
        _keyComparer = keyComparer;
        _keySelector = keySelector;
        Root = null;
        CountAll = 0;
    }
    [MethodImpl(256)]
    public override string ToString() => string.Join(",", ToList());
    List<TValue> list;
    [MethodImpl(256)]
    public List<TValue> ToList()
    {
        list = new List<TValue>();
        ToList(Root);
        return list;
    }
    [MethodImpl(256)]
    private void ToList(Node x)
    {
        if (x == null) return;
        ToList(x.LChild);
        for (int i = 0; i < x.Count; i++) list.Add(x.Value);
        ToList(x.RChild);
    }
    [MethodImpl(256)]
    public string Debug() => Debug(Root, "", "");
    [MethodImpl(256)]
    private string Debug(Node x, string indent, string prefix)
    {
        if (x == null) return "";
        if (indent.Length > 40) return "...";
        var newindent = indent + "  ";
        var ret = "";
        var t = Debug(x.LChild, newindent, "/");
        if (t != "") ret += t;
        ret += $"{indent}{prefix}{(x.Color == 0 ? "B" : "R")}:{x.Value}*{x.Count}<{x.CountSum}";
        t = Debug(x.RChild, newindent, "\\");
        if (t != "") ret += t;
        return ret;
    }
    [MethodImpl(256)]
    public bool Contains(TValue v) => Contains(Root, _keySelector(v));
    [MethodImpl(256)]
    private bool Contains(Node x, TKey k)
    {
        while (true)
        {
            if (x == null) return false;
            if (_keyComparer.Compare(k, x.Key) == 0) return true;
            x = _keyComparer.Compare(k, x.Key) < 0 ? x.LChild : x.RChild;
        }
    }
    [MethodImpl(256)]
    public long Count() => Root == null ? 0 : Root.CountSum;
    [MethodImpl(256)]
    public long Count(TValue v) => Count(Root, _keySelector(v));
    [MethodImpl(256)]
    private long Count(Node x, TKey k)
    {
        while (true)
        {
            if (x == null) return 0;
            if (_keyComparer.Compare(k, x.Key) == 0) return x.Count;
            x = _keyComparer.Compare(k, x.Key) < 0 ? x.LChild : x.RChild;
        }
    }
    [MethodImpl(256)]
    public long UpperBound(TValue v) => UpperBoundKey(_keySelector(v));
    [MethodImpl(256)]
    public long UpperBoundKey(TKey k)
    {
        if (Root == null) return 0;
        Node x = Root;
        long ret = 0;
        while (x != null)
        {
            if (_keyComparer.Compare(k, x.Key) < 0)
            {
                x = x.LChild;
            }
            else
            {
                ret += x.Count + (x.LChild != null ? x.LChild.CountSum : 0);
                x = x.RChild;
            }
        }
        return ret;
    }
    [MethodImpl(256)]
    public long LowerBound(TValue v) => LowerBoundKey(_keySelector(v));
    [MethodImpl(256)]
    public long LowerBoundKey(TKey k)
    {
        if (Root == null) return 0;
        Node x = Root;
        long ret = 0;
        while (x != null)
        {
            if (_keyComparer.Compare(k, x.Key) <= 0)
            {
                x = x.LChild;
            }
            else
            {
                ret += x.Count + (x.LChild != null ? x.LChild.CountSum : 0);
                x = x.RChild;
            }
        }
        return ret;
    }
    public TValue this[long i]
    {
        [MethodImpl(256)]
        get => GetByIndex(i);
    }
    [MethodImpl(256)]
    public TValue GetByIndex(long i)
    {
        if ((ulong)i >= (ulong)CountAll) throw new IndexOutOfRangeException();
        Node x = Root;
        long cnt = 0;
        while (true)
        {
            long lcnt = x.LChild == null ? 0 : x.LChild.CountSum;
            if (i < cnt + lcnt) x = x.LChild;
            else
            {
                cnt += lcnt;
                if (i < cnt + x.Count) return x.Value;
                cnt += x.Count;
                x = x.RChild;
            }
        }
    }
    [MethodImpl(256)]
    private void Rotate(Node x, int dir)
    {
        if (x == null) return;
        Node p = x.Parent;
        Node y = dir == 0 ? x.RChild : x.LChild;
        if (y == null) return;
        if (p == null) Root = y;
        else p.ReplaceChild(x, y);
        y.Parent = p;
        x.Parent = y;
        y.CountSum = x.CountSum;
        x.CountSum -= y.Count;
        if (dir == 0)
        {
            if (y.LChild != null) y.LChild.Parent = x;
            x.RChild = y.LChild;
            y.LChild = x;
            if (y.RChild != null) x.CountSum -= y.RChild.CountSum;
        }
        else
        {
            if (y.RChild != null) y.RChild.Parent = x;
            x.LChild = y.RChild;
            y.RChild = x;
            if (y.LChild != null) x.CountSum -= y.LChild.CountSum;
        }
    }
    [MethodImpl(256)]
    public TValue Max() => MaxNode(Root).Value;
    [MethodImpl(256)]
    private Node MaxNode(Node x)
    {
        while (x.RChild != null) x = x.RChild;
        return x;
    }
    [MethodImpl(256)]
    public TValue Min() => MinNode(Root).Value;
    [MethodImpl(256)]
    private Node MinNode(Node x)
    {
        while (x.LChild != null) x = x.LChild;
        return x;
    }
    [MethodImpl(256)]
    public void Add(TValue v, long cnt = 1)
    {
        if (Root == null) Root = new Node(_keySelector(v), v, cnt);
        else Add(Root, v, cnt);
        CountAll += cnt;
    }
    [MethodImpl(256)]
    private void Add(Node x, TValue v, long cnt)
    {
        TKey k = _keySelector(v);
        while (true)
        {
            if (_keyComparer.Compare(k, x.Key) == 0)
            {
                x.Count += cnt;
                Node t = x;
                while (t != null)
                {
                    t.CountSum += cnt;
                    t = t.Parent;
                }
                return;
            }
            else
            {
                int dir = _keyComparer.Compare(k, x.Key) < 0 ? 0 : 1;
                Node c = dir == 0 ? x.LChild : x.RChild;
                if (c == null)
                {
                    c = new Node(k, v, cnt, x, 1);
                    if (dir == 0) x.LChild = c;
                    else x.RChild = c;
                    Node t = x;
                    while (t != null)
                    {
                        t.CountSum += cnt;
                        t = t.Parent;
                    }
                    AddFix(c);
                    return;
                }
                x = c;
            }
        }
    }
    [MethodImpl(256)]
    private void AddFix(Node x)
    {
        while (true)
        {
            Node p = x.Parent;
            if (p == null) { x.Color = 0; return; }
            if (p.Color == 0) return;
            Node pp = p.Parent;
            if (pp == null) { p.Color = 0; return; }
            int dir = pp.LChild == p ? 0 : 1;
            Node ppc = dir == 0 ? pp.RChild : pp.LChild;
            if (ppc != null && ppc.Color == 1)
            {
                p.Color = 0;
                ppc.Color = 0;
                pp.Color = 1;
                x = pp;
                continue;
            }
            else if ((dir == 0) ^ (x == p.RChild))
            {
                pp.Color = 1;
                p.Color = 0;
                Rotate(pp, dir ^ 1);
                return;
            }
            else
            {
                pp.Color = 1;
                x.Color = 0;
                Rotate(p, dir);
                Rotate(pp, dir ^ 1);
                return;
            }
        }
    }
    [MethodImpl(256)]
    public void RemoveAt(long x) => Remove(Root, GetByIndex(x), 1);
    [MethodImpl(256)]
    public void Remove(TValue v, long cnt = 1) => Remove(Root, v, cnt);
    [MethodImpl(256)]
    private void Remove(Node x, TValue v, long cnt)
    {
        TKey k = _keySelector(v);
        while (true)
        {
            if (x == null) return;
            if (_keyComparer.Compare(k, x.Key) == 0)
            {
                if (x.Count > cnt)
                {
                    CountAll -= cnt;
                    x.Count -= cnt;
                    Node t = x;
                    while (t != null)
                    {
                        t.CountSum -= cnt;
                        t = t.Parent;
                    }
                }
                else
                {
                    cnt = x.Count;
                    CountAll -= cnt;
                    Node p = x.Parent, l = x.LChild, r = x.RChild;
                    Node t = p;
                    while (t != null)
                    {
                        t.CountSum -= cnt;
                        t = t.Parent;
                    }
                    if (l == null)
                    {
                        if (p == null) Root = r;
                        else p.ReplaceChild(x, r);
                        if (r != null)
                        {
                            r.Parent = p;
                            r.Color = 0;
                        }
                    }
                    else if (r == null)
                    {
                        if (p == null) Root = l;
                        else p.ReplaceChild(x, l);
                        l.Parent = p;
                        l.Color = 0;
                    }
                    else
                    {
                        Node y = MinNode(r), z = y.RChild;
                        if (y != r)
                        {
                            t = y.Parent;
                            while (t != x)
                            {
                                t.CountSum -= y.Count;
                                t = t.Parent;
                            }
                            y.Parent.LChild = z;
                            if (z != null) z.Parent = y.Parent;
                            r.Parent = y;
                            y.RChild = r;
                        }
                        y.CountSum = x.CountSum - x.Count;
                        if (l != null) l.Parent = y;
                        y.LChild = l;
                        if (p == null) Root = y;
                        else p.ReplaceChild(x, y);
                        y.Parent = p;
                        y.Color = x.Color;
                        RemoveFix(z);
                    }
                    x.Count = 0;
                }
                return;
            }
            x = _keyComparer.Compare(k, x.Key) < 0 ? x.LChild : x.RChild;
        }
    }
    [MethodImpl(256)]
    private void RemoveFix(Node x)
    {
        while (true)
        {
            if (x == null) return;
            if (x == Root || x.Color == 1)
            {
                x.Color = 0;
                return;
            }
            Node p = x.Parent;
            int dir = p.LChild == x ? 1 : 0;
            Node s = dir == 0 ? p.LChild : p.RChild;
            if (s == null) return;
            if (s.Color == 1)
            {
                p.Color = 1;
                s.Color = 0;
                Rotate(p, dir ^ 1);
                continue;
            }
            else
            {
                Node sl = dir == 1 ? s.LChild : s.RChild;
                Node sr = dir == 0 ? s.LChild : s.RChild;
                int slc = sl == null ? 0 : sl.Color;
                int src = sr == null ? 0 : sr.Color;
                if (slc == 0 && src == 0)
                {
                    s.Color = 1;
                    x = p;
                    continue;
                }
                else if (src == 0)
                {
                    s.Color = 1;
                    sl.Color = 0;
                    Rotate(s, dir);
                    x = sl;
                    continue;
                }
                else
                {
                    s.Color = p.Color;
                    p.Color = 0;
                    sr.Color = 0;
                    Rotate(p, dir ^ 1);
                    return;
                }
            }
        }
    }
}