using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static long NN => long.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    static long[] NMi => ReadLine().Split().Select(c => long.Parse(c) - 1).ToArray();
    static long[][] NMap(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NMi).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        var map = NMap(m);
        var pset = new HashSet<long>();
        var mset = new HashSet<long>();
        var opset = new HashSet<long>();
        var omset = new HashSet<long>();
        var ecset = new HashSet<long>();
        var ocset = new HashSet<long>();
        ecset.Add(0);
        ocset.Add(0);
        foreach (var mi in map)
        {
            pset.Add(mi[0] + mi[1]);
            mset.Add(mi[0] - mi[1]);
            if ((mi[0] + mi[1]) % 2 == 0)
            {
                ecset.Add(mi[0] + mi[1]);
                ecset.Add(Math.Abs(mi[0] - mi[1]));
                ecset.Add(2 * n - 2 - Math.Abs(mi[0] - mi[1]));
            }
            else
            {
                ocset.Add(mi[0] + mi[1]);
                ocset.Add(Math.Abs(mi[0] - mi[1]));
                ocset.Add(2 * n - 2 - Math.Abs(mi[0] - mi[1]));
            }
        }
        var eclist = new List<long>(ecset);
        eclist.Sort();
        var edic = new Dictionary<long, int>();
        for (var i = 0; i < eclist.Count; ++i) edic[eclist[i]] = i;
        var oclist = new List<long>(ocset);
        oclist.Sort();
        var odic = new Dictionary<long, int>();
        for (var i = 0; i < oclist.Count; ++i) odic[oclist[i]] = i;
        var eft = new FenwickTree(eclist.Count);
        var oft = new FenwickTree(oclist.Count);
        var ans = 0L;
        foreach (var plus in pset)
        {
            if (plus % 2 == 0)
            {
                ans += Math.Min(plus + 1, 2 * n - 1 - plus);
                // WriteLine($"/: {Math.Min(plus + 1, 2 * n - 1 - plus)}");
                eft.Add(edic[plus], 1);
            }
            else
            {
                ans += Math.Min(plus + 1, 2 * n - 1 - plus);
                // WriteLine($"/: {Math.Min(plus + 1, 2 * n - 1 - plus)}");
                oft.Add(odic[plus], 1);
            }
        }
        foreach (var mi in mset)
        {
            var left = Math.Abs(mi);
            var right = 2 * n - 2 - Math.Abs(mi);
            if (mi % 2 == 0)
            {
                ans += (right - left) / 2 + 1 - eft.Sum(edic[right]) + eft.Sum(edic[left] - 1);
                // WriteLine($"({right} - {left}) / 2 + 1 - {eft.Sum(edic[right])} + {eft.Sum(edic[left] - 1)}");
            }
            else
            {
                ans += (right - left) / 2 + 1 - oft.Sum(odic[right]) + oft.Sum(odic[left] - 1);
                // WriteLine($"({right} - {left}) / 2 + 1 - {oft.Sum(odic[right])} + {oft.Sum(odic[left] - 1)}");
            }
        }
        WriteLine(ans);
    }
    class FenwickTree
    {
        int size;
        long[] tree;
        public FenwickTree(int size)
        {
            this.size = size;
            tree = new long[size + 2];
        }
        public void Add(int index, int value)
        {
            ++index;
            for (var x = index; x <= size; x += (x & -x)) tree[x] += value;
        }
        /// <summary>先頭からindexまでの和(include index)</summary>
        public long Sum(int index)
        {
            if (index < 0) return 0;
            ++index;
            var sum = 0L;
            for (var x = index; x > 0; x -= (x & -x)) sum += tree[x];
            return sum;
        }
        /// <summary>Sum(x) >= value となる最小のxを求める</summary>
        // 各要素は非負であること
        public int LowerBound(long value)
        {
            if (value < 0) return -1;
            var x = 0;
            var b = 1;
            while (b * 2 <= size) b <<= 1;
            for (var k = b; k > 0; k >>= 1)
            {
                if (x + k <= size && tree[x + k] < value)
                {
                    value -= tree[x + k];
                    x += k;
                }
            }
            return x;
        }
    }
}