namespace AtCoder; #nullable enable using System.Numerics; static class Extensions { public static T[] Repeat(this int time, Func F) => Enumerable.Range(0, time).Select(_ => F()).ToArray(); } readonly record struct ModInt : IEqualityOperators, IAdditiveIdentity, IAdditionOperators, IUnaryNegationOperators, ISubtractionOperators, IMultiplicativeIdentity, IMultiplyOperators, IDivisionOperators { int V { get; init; } public const int Mod = 998244353; public ModInt(long value) { var v = value % Mod; if (v < 0) v += Mod; V = (int)v; } ModInt(int value) { V = value; } public static implicit operator ModInt(long v) => new(v); public static implicit operator int(ModInt modInt) => modInt.V; public static ModInt operator +(ModInt a, ModInt b) { var v = a.V + b.V; if (v >= Mod) v -= Mod; return new(v); } public static ModInt operator -(ModInt a) => new(a.V == 0 ? 0 : Mod - a.V); public static ModInt operator -(ModInt a, ModInt b) { var v = a.V - b.V; if (v < 0) v += Mod; return new(v); } public static ModInt operator *(ModInt a, ModInt b) => new((int)((long)a.V * b.V % Mod)); public static ModInt operator /(ModInt a, ModInt b) { if (b == 0) throw new DivideByZeroException(); var (d, x, _) = ExtendedGcd(b.V, Mod); if (d > 1) throw new DivideByZeroException(); return x * a.V; } public ModInt Power(long p) { if (p < 0) return (MultiplicativeIdentity / V).Power(-p); long res = 1; long k = V; while (p > 0) { if ((p & 1) > 0) res = res * k % Mod; k = k * k % Mod; p >>= 1; } return res; } static (long d, long x, long y) ExtendedGcd(long a, long b) { if (b == 0) return (a, 1, 0); var (d, x, y) = ExtendedGcd(b, a % b); return (d, y, x - a / b * y); } public static ModInt AdditiveIdentity => new(0); public static ModInt MultiplicativeIdentity => new(1); public override string ToString() => V.ToString(); } readonly struct Matrix where T : IAdditiveIdentity, IAdditionOperators, IMultiplicativeIdentity, IMultiplyOperators { T[,] V { get; init; } public T this[int i, int j] { get => V[i, j]; set { V[i, j] = value; } } public int X { get => V.GetLength(0); } public int Y { get => V.GetLength(1); } public Matrix(T[,] matrix) { V = new T[matrix.GetLength(0), matrix.GetLength(1)]; Array.Copy(matrix, V, matrix.Length); } public static Matrix IdentityMatrix(int size) { var v = new T[size, size]; for (var i = 0; i < size; i++) for (var j = 0; j < size; j++) v[i, j] = T.AdditiveIdentity; for (var i = 0; i < size; i++) v[i, i] = T.MultiplicativeIdentity; return new(v); } public static Matrix operator +(Matrix a, Matrix b) { if (a.X != b.X || a.Y != b.Y) throw new InvalidOperationException(); var (v, x, y) = (new T[a.X, a.Y], a.X, a.Y); for (var i = 0; i < x; i++) for (var j = 0; j < y; j++) v[i, j] = a[i, j] + b[i, j]; return new(v); } public static Matrix operator *(Matrix a, Matrix b) { if (a.Y != b.X) throw new InvalidOperationException(); var (v, x, y, z) = (new T[a.X, b.Y], a.X, b.Y, a.Y); for (var i = 0; i < x; i++) for (var j = 0; j < y; j++) { var e = T.AdditiveIdentity; for (var k = 0; k < z; k++) e += a[i, k] * b[k, j]; v[i, j] = e; } return new(v); } public Matrix Power(long k) { if (X != Y) throw new InvalidOperationException(); var c = IdentityMatrix(X); var c2 = this; while (k > 0) { if ((k & 1) > 0) c *= c2; c2 *= c2; k >>= 1; } return c; } } class AtCoder { object? Solve() { var n = Int(); var k = Int(); var vi = new ModInt[6, 1]; vi[0, 0] = 1; var v = new Matrix(vi); var mi = new ModInt[6, 6]; var o = (ModInt)1 / 6; for (var i = 0; i < n; i++) for (var j = 0; j < n; j++) mi[i, j] = o; var a = new Matrix(mi); v = a.Power(n) * v; return v[k, 0]; } public static void Main() => new AtCoder().Run(); public void Run() { var res = Solve(); if (res != null) { if (res is bool yes) res = yes ? "Yes" : "No"; sw.WriteLine(res); } sw.Flush(); } string[] input = Array.Empty(); int iter = 0; readonly StreamWriter sw = new(Console.OpenStandardOutput()) { AutoFlush = false }; #pragma warning disable IDE0051 string String() { while (iter >= input.Length) (input, iter) = (Console.ReadLine()!.Split(' '), 0); return input[iter++]; } T Input() where T : IParsable => T.Parse(String(), null); int Int() => Input(); void Out(object? x, string? separator = null) { separator ??= Environment.NewLine; if (x is System.Collections.IEnumerable obj and not string) { var firstLine = true; foreach (var item in obj) { if (!firstLine) sw.Write(separator); firstLine = false; sw.Write(item); } } else sw.Write(x); sw.WriteLine(); } #pragma warning restore IDE0051 }