// ReSharper disable RedundantUsingDirective #nullable disable using System.Collections; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Diagnostics; using System.Runtime.CompilerServices; using System.IO; using System.Linq; using System.Text; using System.Numerics; using System.Runtime.Intrinsics.X86; using static Solve.Input; using static Solve.Lib; using static Solve.Output; using static System.Math; // Resharper restore RedundantUsingDirective using System; using Solve.Libraries.ModInt; // ReSharper disable InconsistentNaming namespace Solve { public partial class Solver { public void Main() { var (N, P) = Int.ReadMulti(); var cnt = 0; var fact = ModInt.One; for (int i = 2; i <= N; ++i) { int k = i; while (k % P == 0) { ++cnt; k /= P; } fact *= i; } // N! ^ N! mod 10^9+7 var ans = fact; for (int i = 2; i <= N; ++i) { ans = ModInt.ModPow(ans, i); } Print(ans * cnt); } public const long MOD = 998244353; } public static class Lib { [MethodImpl(256)] public static bool Assert(in bool b, in string message = null) => b ? true : throw new Exception(message ?? "Assert failed."); [MethodImpl(256)] public static string JoinSpace(this IEnumerable source) => source.Join(" "); [MethodImpl(256)] public static string JoinEndline(this IEnumerable source) => source.Join("\n"); [MethodImpl(256)] public static string Join(this IEnumerable source, string s) => string.Join(s, source); [MethodImpl(256)] public static string Join(this IEnumerable source, char c) => string.Join(c.ToString(), source); public static int Gcd(int a, int b) => (int) Gcd((long) a, b); public static long Gcd(long a, long b) { while (true) { if (a < b) (a, b) = (b, a); if (a % b == 0) return b; (a, b) = (b, a % b); } } public static long Lcm(long a, long b) => a / Gcd(a, b) * b; public static bool IsPrime(long value) { if (value <= 1) return false; for (long i = 2; i * i <= value; ++i) if (value % i == 0) return false; return true; } public static long Pow(long a, int b) { long res = 1; while (b > 0) { if (b % 2 != 0) res *= a; a *= a; b >>= 1; } return res; } public static int PowMod(long a, long b, int p) => (int) PowMod(a, b, (long) p); public static long PowMod(long a, long b, long p) { long res = 1; while (b > 0) { if (b % 2 != 0) res = res * a % p; a = a * a % p; b >>= 1; } return res; } public static IEnumerable Factors(long n) { Assert(n >= 0, "n must be greater than 0."); for (long i = 1; i * i <= n; ++i) { var div = DivRem(n, i, out var rem); if (rem > 0) continue; yield return div; if (i != div) yield return i; } } public static IEnumerable Factors(int n) => Factors((long) n).Select(Convert.ToInt32); [MethodImpl(256)] public static int DivCeil(int a, int b) => (a + b - 1) / b; [MethodImpl(256)] public static long DivCeil(long a, long b) => (a + b - 1) / b; public static IEnumerable Permutations(IEnumerable src) { var ret = new List(); Search(ret, new Stack(), src.ToArray()); return ret; static void Search(ICollection perms, Stack stack, T[] a) { int N = a.Length; if (N == 0) perms.Add(stack.Reverse().ToArray()); else { var b = new T[N - 1]; Array.Copy(a, 1, b, 0, N - 1); for (int i = 0; i < a.Length; ++i) { stack.Push(a[i]); Search(perms, stack, b); if (i < b.Length) b[i] = a[i]; stack.Pop(); } } } } public static IEnumerable AllSubsets(int n) { Assert(n < 31, "n must be less than 31."); var range = Range(n).ToArray(); for (int s = 0; s < 1 << n; s++) yield return Array.ConvertAll(range, i => (s & (1 << i)) > 0); } public static IEnumerable AllSubsets(T[] array) { foreach (bool[] subset in AllSubsets(array.Length)) yield return subset.Select((x, i) => (f: x, i)).Where(x => x.f).Select(x => array[x.i]).ToArray(); } public static long BinarySearch(long low, long high, Func expression) { while (low < high) { long middle = (high - low) / 2 + low; if (!expression(middle)) high = middle; else low = middle + 1; } return high; } public static int LowerBound(T[] arr, int start, int end, T value, IComparer comparer) { int low = start; int high = end; while (low < high) { var mid = ((high - low) >> 1) + low; if (comparer.Compare(arr[mid], value) < 0) low = mid + 1; else high = mid; } return low; } public static int LowerBound(T[] arr, T value) where T : IComparable => LowerBound(arr, 0, arr.Length, value, Comparer.Default); public static int UpperBound(T[] arr, int start, int end, T value, IComparer comparer) { var (low, high) = (start, end); while (low < high) { var mid = ((high - low) >> 1) + low; if (comparer.Compare(arr[mid], value) <= 0) low = mid + 1; else high = mid; } return low; } public static int UpperBound(T[] arr, T value) => UpperBound(arr, 0, arr.Length, value, Comparer.Default); [MethodImpl(256)] public static IEnumerable Repeat(TResult value, int count) => Enumerable.Repeat(value, count); [MethodImpl(256)] public static string AsString(this IEnumerable source) => new string(source.ToArray()); public static IEnumerable CumulativeSum(this IEnumerable source) { long sum = 0; foreach (var item in source) yield return sum += item; } public static IEnumerable CumulativeSum(this IEnumerable source) { int sum = 0; foreach (var item in source) yield return sum += item; } [MethodImpl(256)] public static bool IsIn(this T value, T l, T r) where T : IComparable => l.CompareTo(r) > 0 ? throw new ArgumentException() : l.CompareTo(value) <= 0 && value.CompareTo(r) < 0; [MethodImpl(256)] public static bool IsIn(this in int value, in Range range) => value.IsIn(range.Start.Value, range.End.Value); [MethodImpl(256)] public static bool IsIn(this in Index value, in Range range) => value.IsFromEnd && value.Value.IsIn(range.Start.Value, range.End.Value); public static IEnumerable Range(int start, int end, int step = 1) { for (var i = start; i < end; i += step) yield return i; } public static IEnumerable Range(int end) => Range(0, end); public static IEnumerable Range(Range range, int step = 1) => Range(range.Start.Value, range.End.Value, step); [MethodImpl(256)] public static T[] Sorted(this T[] arr) where T : IComparable { var array = arr[..]; Array.Sort(array); return array; } [MethodImpl(256)] public static T[] Sorted(this T[] arr, Func selector) where U : IComparable { var array = arr[..]; Array.Sort(array, (a, b) => selector(a).CompareTo(selector(b))); return array; } [MethodImpl(256)] public static T[] SortedDescending(this T[] arr) where T : IComparable { var array = arr[..]; Array.Sort(array, (a, b) => b.CompareTo(a)); return array; } [MethodImpl(256)] public static T[] SortedDescending(this T[] arr, Func selector) where U : IComparable { var array = arr[..]; Array.Sort(array, (a, b) => selector(b).CompareTo(selector(a))); return array; } public static T[] Unique(this IEnumerable arr) { var source = arr.ToArray(); var ret = new List(source.Length); var set = new SortedSet(); ret.AddRange(source.Where(val => set.Add(val))); return ret.ToArray(); } [MethodImpl(256)] public static bool chmin(ref T a, T b) where T : IComparable { if (a.CompareTo(b) > 0) { a = b; return true; } return false; } [MethodImpl(256)] public static bool chmax(ref T a, T b) where T : IComparable { if (a.CompareTo(b) < 0) { a = b; return true; } return false; } [MethodImpl(256)] public static bool ChangeToMin(this ref T a, T b) where T : struct, IComparable => chmin(ref a, b); [MethodImpl(256)] public static bool ChangeToMax(this ref T a, T b) where T : struct, IComparable => chmax(ref a, b); public static T[] InitArray(int n, Func init) { var res = new T[n]; for (int i = 0; i < n; i++) res[i] = init(i); return res; } public static T[] InitArray(int n, Func init) => InitArray(n, _ => init()); public static T[] InitArray(int n, T t) where T : struct => InitArray(n, _ => t); public static T[][] JaggedArray2D(int a, int b, T defaultValue = default) { var ret = new T[a][]; for (int i = 0; i < a; ++i) ret[i] = Enumerable.Repeat(defaultValue, b).ToArray(); return ret; } public static T[,] Array2D(int h, int w, T defaultValue = default) { var ret = new T[h, w]; for (int i = 0; i < h; ++i) for (int j = 0; j < w; ++j) ret[i, j] = defaultValue; return ret; } public static T[,] Array2D(int h, int w, Func factory) { var ret = new T[h, w]; for (int i = 0; i < h; ++i) for (int j = 0; j < w; ++j) ret[i, j] = factory(i, j); return ret; } public static T[,] To2DArray(this T[][] array) { if (!array.Any()) return new T[0, 0]; int len = array[0].Length; if (array.Any(x => x.Length != len)) throw new ArgumentException("Length of each array must be same.", nameof(array)); var ret = new T[array.Length, len]; for (int i = 0; i < array.Length; ++i) for (int j = 0; j < len; ++j) ret[i, j] = array[i][j]; return ret; } [MethodImpl(256)] public static T Min(params T[] col) => col.Min(); [MethodImpl(256)] public static T Max(params T[] col) => col.Max(); [MethodImpl(256)] public static IEnumerable<(T, int)> WithIndex(this IEnumerable source) => source.Select((x, i) => (x, i)); [MethodImpl(256)] public static (T, U, V)[] Zip( IReadOnlyCollection t, IReadOnlyCollection u, IReadOnlyCollection v ) { Assert(t.Count == u.Count && u.Count == v.Count); return t.Zip(u, (a, b) => (a, b)) .Zip(v, (tuple, c) => (tuple.a, tuple.b, c)).ToArray(); } [MethodImpl(256)] public static void Repeat(in int start, in int end, Action func) { for (int i = start; i < end; ++i) func(i); } [MethodImpl(256)] public static void Repeat(in int end, Action func) => Repeat(0, end, func); [MethodImpl(256)] public static void RepeatClosed(in int end, Action func) => Repeat(1, end + 1, func); [MethodImpl(256)] public static void RepeatReverse(in int end, Action func) { for (int i = end - 1; i >= 0; --i) func(i); } [MethodImpl(256)] public static void Each(this IEnumerable source, Action func) { foreach (var item in source) func(item); } [MethodImpl(256)] public static void EachWithIndex(this IEnumerable source, Action func) { int index = 0; foreach (var item in source) func(item, index++); } public static IEnumerable Scan(this IEnumerable source, U seed, Func func) { var tmp = seed; foreach (var v in source) yield return func(tmp, v); } [MethodImpl(256)] public static int Bit(in int x) => 1 << x; [MethodImpl(256)] public static long BitLong(in int x) => 1L << x; public static (T, U)[] Zip(this (T[], U[]) arrays) => arrays.Item1.Zip(arrays.Item2).ToArray(); public static U Pipe(this T self, Func func) => func(self); public static void Pipe(this T self, Action func) => func(self); } public class UnorderedMap : Dictionary { public new U this[T k] { get => TryGetValue(k, out var v) ? v : base[k] = default; set => base[k] = value; } } public class Map : SortedDictionary { readonly U _default; public Map(U defaultValue = default) { _default = defaultValue; } public new U this[T k] { get => TryGetValue(k, out var v) ? v : base[k] = _default; set => base[k] = value; } } public class Scanner { public Scanner() { _deconstructer = new Deconstructer(this); } public readonly struct Deconstructer { public Deconstructer(Scanner scanner) => _sc = scanner; readonly Scanner _sc; public void Deconstruct(out T _1, out T _2) => (_1, _2) = (_sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3) => (_1, _2, _3) = (_sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4) => (_1, _2, _3, _4) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5) => (_1, _2, _3, _4, _5) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6) => (_1, _2, _3, _4, _5, _6) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7) => (_1, _2, _3, _4, _5, _6, _7) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7, out T _8) => (_1, _2, _3, _4, _5, _6, _7, _8) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7, out T _8, out T _9) => (_1, _2, _3, _4, _5, _6, _7, _8, _9) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); public void Deconstruct(out T _1, out T _2, out T _3, out T _4, out T _5, out T _6, out T _7, out T _8, out T _9, out T _10) => (_1, _2, _3, _4, _5, _6, _7, _8, _9, _10) = (_sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read(), _sc.Read()); } readonly Deconstructer _deconstructer; public T next() => Read(); public T Read() => Next(); public Deconstructer ReadMulti() => _deconstructer; IEnumerable Enumerable(int N) { for (int i = 0; i < N; ++i) yield return Read(); } public T[] ReadArray(in int N) => Enumerable(N).ToArray(); public List ReadList(in int N) => Enumerable(N).ToList(); public T[,] ReadArray2d(in int N, in int M) => Next2DArray(N, M); public T[][] ReadListArray(in int n) { var ret = new T[n][]; for (int i = 0; i < n; i++) ret[i] = ReadArray(Next()); return ret; } } public static class Input { const char _separator = ' '; static readonly Queue _input = new Queue(); static readonly StreamReader sr = #if FILE new StreamReader("in.txt"); #else new StreamReader(Console.OpenStandardInput()); #endif public static string ReadLine => sr.ReadLine(); static string ReadStr() => Next(); static int ReadInt() => int.Parse(Next()); static long ReadLong() => long.Parse(Next()); static ulong ReadULong() => ulong.Parse(Next()); static double ReadDouble() => double.Parse(Next()); static BigInteger ReadBigInteger() => BigInteger.Parse(Next()); public static string Next() { if (_input.Any()) return _input.Dequeue(); foreach (var val in sr.ReadLine().Split(_separator)) _input.Enqueue(val); return _input.Dequeue(); } public static T Next() => default(T) switch { sbyte _ => (T) (object) (sbyte) ReadInt(), short _ => (T) (object) (short) ReadInt(), int _ => (T) (object) ReadInt(), long _ => (T) (object) ReadLong(), byte _ => (T) (object) (byte) ReadULong(), ushort _ => (T) (object) (ushort) ReadULong(), uint _ => (T) (object) (uint) ReadULong(), ulong _ => (T) (object) ReadULong(), float _ => (T) (object) (float) ReadDouble(), double _ => (T) (object) ReadDouble(), string _ => (T) (object) ReadStr(), char _ => (T) (object) ReadStr()[0], BigInteger _ => (T) (object) ReadBigInteger(), _ => typeof(T) == typeof(string) ? (T) (object) ReadStr() : throw new NotSupportedException(), }; public static (T, U) Next() => (Next(), Next()); public static (T, U, V) Next() => (Next(), Next(), Next()); public static (T, U, V, W) Next() => (Next(), Next(), Next(), Next()); public static (T, U, V, W, X) Next() => (Next(), Next(), Next(), Next(), Next()); public static T[] NextArray(in int size) { var ret = new T[size]; for (int i = 0; i < size; ++i) ret[i] = Next(); return ret; } public static T[,] Next2DArray(int n, in int m) { var ret = new T[n, m]; for (int i = 0; i < n; ++i) for (int j = 0; j < m; ++j) ret[i, j] = Next(); return ret; } public static (T[], U[]) NextArray(in int size) { var ret1 = new T[size]; var ret2 = new U[size]; for (int i = 0; i < size; ++i) (ret1[i], ret2[i]) = Next(); return (ret1, ret2); } public static (T[], U[], V[]) NextArray(in int size) { var ret1 = new T[size]; var ret2 = new U[size]; var ret3 = new V[size]; for (int i = 0; i < size; ++i) (ret1[i], ret2[i], ret3[i]) = Next(); return (ret1, ret2, ret3); } public static (T[], U[], V[], W[]) NextArray(in int size) { var ret1 = new T[size]; var ret2 = new U[size]; var ret3 = new V[size]; var ret4 = new W[size]; for (int i = 0; i < size; ++i) (ret1[i], ret2[i], ret3[i], ret4[i]) = Next(); return (ret1, ret2, ret3, ret4); } } public static class Output { [MethodImpl(256)] public static void Print() => Console.WriteLine(); [MethodImpl(256)] public static void Print(in string s, bool endline = true) { if (endline) Console.WriteLine(s); else Console.Write(s); } [MethodImpl(256)] public static void Print(in char s, bool endline = true) { if (endline) Console.WriteLine(s); else Console.Write(s); } [MethodImpl(256)] public static void Print(in int v, bool endline = true) { if (endline) Console.WriteLine(v); else Console.Write(v); } [MethodImpl(256)] public static void Print(in long v, bool endline = true) { if (endline) Console.WriteLine(v); else Console.Write(v); } [MethodImpl(256)] public static void Print(in ulong v, bool endline = true) { if (endline) Console.WriteLine(v); else Console.Write(v); } [MethodImpl(256)] public static void Print(in bool b) => PrintBool(b); [MethodImpl(256)] public static void Print(in object v) => Console.WriteLine(v); [MethodImpl(256)] public static void Print(in IEnumerable array, string separator = " ") => Console.WriteLine(array.Join(separator)); [MethodImpl(256)] public static void MultiPrint(params T[] t) => Print(t); [MethodImpl(256)] public static void PrintExit(in string s, bool endline = true, int exitCode = 0) { if (endline) Console.WriteLine(s); else Console.Write(s); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in char s, bool endline = true, int exitCode = 0) { if (endline) Console.WriteLine(s); else Console.Write(s); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in int v, bool endline = true, int exitCode = 0) { if (endline) Console.WriteLine(v); else Console.Write(v); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in long v, bool endline = true, int exitCode = 0) { if (endline) Console.WriteLine(v); else Console.Write(v); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in ulong v, bool endline = true, int exitCode = 0) { if (endline) Console.WriteLine(v); else Console.Write(v); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in bool b, int exitCode = 0) { PrintBool(b); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in object v, int exitCode = 0) { Console.WriteLine(v); Environment.Exit(exitCode); } [MethodImpl(256)] public static void PrintExit(in IEnumerable array, string separator = " ", int exitCode = 0) { Console.WriteLine(array.Join(separator)); Environment.Exit(exitCode); } #if LOCAL [MethodImpl(256)] public static void DebugPrint(in T value, bool endline = true) { if (endline) Console.WriteLine(value); else Console.Write(value); } #else public static void DebugPrint(params object[] obj) { } #endif [MethodImpl(256)] static void PrintBool(in bool val, in string yes = null, in string no = null) => Print(val ? yes ?? _yes : no ?? _no); static string _yes = "Yes", _no = "No"; public static void SetYesNoString(in YesNoType t) => (_yes, _no) = YesNoString[t]; public static void SetYesNoString(in string yes, in string no) => (_yes, _no) = (yes, no); static readonly Dictionary YesNoString = new Dictionary { {YesNoType.Default, ("Yes", "No")}, {YesNoType.Yes_No, ("Yes", "No")}, {YesNoType.YES_NO, ("YES", "NO")}, {YesNoType.Upper, ("YES", "NO")}, {YesNoType.yes_no, ("yes", "no")}, {YesNoType.Lower, ("yes", "no")}, {YesNoType.Possible_Impossible, ("Possible", "Impossible")}, {YesNoType.Yay, ("Yay!", ":(")}, }; public static readonly (string yes, string no) YN_Possible = ("Possible", "Impossible"), YN_lower = ("yes", "no"), YN_upper = ("YES", "NO"), YN_Yay = ("Yay!", ":("); public static void Yes() => Print(_yes); public static void No() => Print(_no); [MethodImpl(256)] public static void YesExit(int exitCode = 0) { Yes(); Console.Out.Flush(); Environment.Exit(exitCode); } [MethodImpl(256)] public static void NoExit(int exitCode = 0) { No(); Console.Out.Flush(); Environment.Exit(exitCode); } public const string endl = "\n"; public enum YesNoType { Default, Yes_No, YES_NO, Upper, yes_no, Lower, Possible_Impossible, Yay } } public class Program { public static void Main(string[] args) { var sw = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false}; Console.SetOut(sw); new Solver().Main(); Console.Out.Flush(); } } partial class Solver { readonly Scanner Int; readonly Scanner Long; readonly Scanner String; public Solver() => (Int, String, Long) = (new Scanner(), new Scanner(), new Scanner()); const int INF = 1000000010; const long LINF = 1000000000000000100; const double EPS = 1e-8; public static readonly int[] dx = {-1, 0, 0, 1, -1, -1, 1, 1}, dy = {0, 1, -1, 0, -1, 1, -1, 1}; } } namespace Solve.Libraries.ModInt { [DebuggerDisplay("{" + nameof(Value) + "}")] public struct ModInt : IEquatable, IComparable { public const int MOD = 1_000_000_007; // public const int MOD = 998_244_353; long _value; public static readonly ModInt Zero = new ModInt(0); public static readonly ModInt One = new ModInt(1); public ModInt(in long value) => _value = (value % MOD + MOD) % MOD; public int Value => (int) _value; public ModInt Invert => ModPow(this, MOD - 2); static List _factMemo = new List { 1, 1 }; public static ModInt operator -(ModInt value) { value._value = MOD - value._value; return value; } public static ModInt operator +(ModInt left, in ModInt right) { left._value += right._value; if (left._value >= MOD) left._value -= MOD; return left; } public static ModInt operator -(ModInt left, in ModInt right) { left._value -= right._value; if (left._value < 0) left._value += MOD; return left; } public static ModInt operator *(ModInt left, in ModInt right) => left._value * right._value % MOD; public static ModInt operator /(ModInt left, in ModInt right) => left * right.Invert; public static ModInt operator ++(ModInt value) { if (value._value == MOD - 1) value._value = 0; else value._value++; return value; } public static ModInt operator --(ModInt value) { if (value._value == 0) value._value = MOD - 1; else value._value--; return value; } public static bool operator ==(ModInt left, in ModInt right) => left.Equals(right); public static bool operator !=(ModInt left, in ModInt right) => !left.Equals(right); public static implicit operator ModInt(in int value) => new ModInt(value); public static implicit operator ModInt(in long value) => new ModInt(value); public static explicit operator int(ModInt m) => m.Value; public static ModInt ModPow(ModInt value, long exponent) { var r = new ModInt(1); for (; exponent > 0; value *= value, exponent >>= 1) if ((exponent & 1) == 1) r *= value; return r; } public static ModInt ModFactorial(int value) { if (_factMemo.Count > value) return _factMemo[value]; for (int i = _factMemo.Count; i <= value; ++i) { _factMemo.Add(_factMemo[i - 1] * i); } return _factMemo[value]; } public static ModInt ModCombination(int n, int r) { if (n < r) return Zero; return ModFactorial(n) / ModFactorial(r) / ModFactorial(n - r); } public bool Equals(ModInt other) => _value == other._value; public override bool Equals(object obj) => obj is ModInt m && Equals(m); public override int GetHashCode() => _value.GetHashCode(); public override string ToString() => _value.ToString(); public int CompareTo(ModInt other) => _value.CompareTo(other._value); } }