using AtCoder; using AtCoder.Internal; using Kzrnm.Competitive.IO; using System; using System.Buffers.Text; using System.Collections.Generic; using System.Diagnostics; using System.IO; using System.Runtime.CompilerServices; using System.Runtime.Intrinsics.X86; using System.Text; namespace YC370.Problems { using ModInt = StaticModInt; internal partial class ProblemB { static void Solve() { var N = cr.Int(); var M = cr.Int(); ModInt ans = 1; var p = new ModInt[1000050]; p[0] = 1; for (int i = 1; i < 1000020; i++) p[i] = p[i - 1] * i; for(int i = 0; i < N; i++) { var m = M / (N - i); ans *= p[M] / (p[M - m] * p[m]); M -= m; } cw.WriteLine(ans); } } } #region Dependency resolution namespace YC370.Problems { internal partial class ProblemB { static ConsoleReader cr; static ConsoleWriter cw; #if COMPETITIVE public ProblemB(string outputFilePath = null, bool solving = true) #else static void Main(string[] args) #endif { #if COMPETITIVE SourceExpander.Expander.Expand(outputFilePath: outputFilePath); #endif if (cw != null) cw.Dispose(); cr = new ConsoleReader(); cw = new ConsoleWriter(); #if COMPETITIVE if (solving) #endif Solve(); cw.Dispose(); } } } #endregion #region Expanded by https://github.com/kzrnm/SourceExpander namespace AtCoder.Internal{public class Barrett{public readonly uint Mod;internal readonly ulong IM;public Barrett(uint m){Mod=m;IM=unchecked((ulong)-1)/m+1;}[MethodImpl(256)]public uint Mul(uint a,uint b){var z=(ulong)a*b;if(Bmi2.X64.IsSupported){var x=Bmi2.X64.MultiplyNoFlags(z,IM);var v=unchecked((uint)(z-x*Mod));if(Mod<=v)v+=Mod;return v;}return(uint)(z%Mod);}}} namespace AtCoder.Internal{public static class InternalMath{private static readonly DictionaryprimitiveRootsCache=new Dictionary(){{2,1},{167772161,3},{469762049,3},{754974721,11},{998244353,3}};[MethodImpl(256)]public static int PrimitiveRoot()where TMod:struct,IStaticMod{uint m=default(TMod).Mod;if(primitiveRootsCache.TryGetValue(m,out var p)){return p;}return primitiveRootsCache[m]=PrimitiveRootCalculate();}static int PrimitiveRootCalculate()where TMod:struct,IStaticMod{int m=(int)default(TMod).Mod;Spandivs=stackalloc int[20];divs[0]=2;int cnt=1;int x=(m-1)/2;while(x%2==0){x>>=1;}for(int i=3;(long)i*i<=x;i+=2){if(x%i==0){divs[cnt++]=i;while(x%i==0){x/=i;}}}if(x>1){divs[cnt++]=x;}divs=divs.Slice(0,cnt);for(int g=2;;g++){foreach(var d in divs)if(new StaticModInt(g).Pow((m-1)/d).Value==1)goto NEXT;return g;NEXT:{}}}[MethodImpl(256)]public static(long,long)InvGCD(long a,long b){a=SafeMod(a,b);if(a==0)return(b,0);long s=b,t=a;long m0=0,m1=1;long u;while(true){if(t==0){if(m0<0)m0+=b/s;return(s,m0);}u=s/t;s-=t*u;m0-=m1*u;if(s==0){if(m1<0)m1+=b/t;return(t,m1);}u=t/s;t-=s*u;m1-=m0*u;}}[MethodImpl(256)]public static long SafeMod(long x,long m){x%=m;if(x<0)x+=m;return x;}[MethodImpl(256)]public static bool IsPrime(int n){if(n<=1)return false;if(n==2||n==7||n==61)return true;if(n%2==0)return false;long d=n-1;while(d%2==0)d/=2;ReadOnlySpanbases=stackalloc byte[3]{2,7,61};foreach(long a in bases){long t=d;long y=PowMod(a,t,n);while(t!=n-1&&y!=1&&y!=n-1){y=y*y%n;t<<=1;}if(y!=n-1&&t%2==0){return false;}}return true;}[MethodImpl(256)]private static long PowMod(long x,long n,int m){if(m==1)return 0;Barrett barrett=new Barrett((uint)m);uint r=1,y=(uint)SafeMod(x,m);while(0>=1;}return r;}[MethodImpl(256)]public static ulong FloorSumUnsigned(ulong n,ulong m,ulong a,ulong b){ulong ans=0;while(true){if(a>=m){ans+=(n-1)*n/2*(a/m);a%=m;}if(b>=m){ans+=n*(b/m);b%=m;}ulong yMax=a*n+b;if(yMax1000000007;public bool IsPrime=>true;}public readonly struct Mod998244353:IStaticMod{public uint Mod=>998244353;public bool IsPrime=>true;}public readonly struct StaticModInt:IEquatable>,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 StaticModIntZero=>default;public static StaticModIntOne=>new StaticModInt(1u);[MethodImpl(256)]public static StaticModIntRaw(int v){var u=unchecked((uint)v);return new StaticModInt(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 StaticModIntoperator ++(StaticModIntv){var x=v._v+1;if(x==op.Mod){x=0;}return new StaticModInt(x);}[MethodImpl(256)]public static StaticModIntoperator --(StaticModIntv){var x=v._v;if(x==0){x=op.Mod;}return new StaticModInt(x-1);}[MethodImpl(256)]public static StaticModIntoperator+(StaticModIntlhs,StaticModIntrhs){var v=lhs._v+rhs._v;if(v>=op.Mod){v-=op.Mod;}return new StaticModInt(v);}[MethodImpl(256)]public static StaticModIntoperator-(StaticModIntlhs,StaticModIntrhs){unchecked{var v=lhs._v-rhs._v;if(v>=op.Mod){v+=op.Mod;}return new StaticModInt(v);}}[MethodImpl(256)]public static StaticModIntoperator*(StaticModIntlhs,StaticModIntrhs)=>new StaticModInt((uint)((ulong)lhs._v*rhs._v%op.Mod));[MethodImpl(256)]public static StaticModIntoperator/(StaticModIntlhs,StaticModIntrhs)=>lhs*rhs.Inv();[MethodImpl(256)]public static StaticModIntoperator+(StaticModIntv)=>v;[MethodImpl(256)]public static StaticModIntoperator-(StaticModIntv)=>new StaticModInt(v._v==0?0:op.Mod-v._v);[MethodImpl(256)]public static bool operator==(StaticModIntlhs,StaticModIntrhs)=>lhs._v==rhs._v;[MethodImpl(256)]public static bool operator!=(StaticModIntlhs,StaticModIntrhs)=>lhs._v!=rhs._v;[MethodImpl(256)]public static implicit operator StaticModInt(int v)=>new StaticModInt(v);[MethodImpl(256)]public static implicit operator StaticModInt(uint v)=>new StaticModInt((long)v);[MethodImpl(256)]public static implicit operator StaticModInt(long v)=>new StaticModInt(v);[MethodImpl(256)]public static implicit operator StaticModInt(ulong v)=>new StaticModInt(v);[MethodImpl(256)]public StaticModIntPow(long n){var x=this;var r=new StaticModInt(1U);while(n>0){if((n&1)>0){r*=x;}x*=x;n>>=1;}return r;}[MethodImpl(256)]public StaticModIntInv(){if(op.IsPrime){return Pow(op.Mod-2);}else{var(g,x)=InternalMath.InvGCD(_v,op.Mod);return new StaticModInt(x);}}public override string ToString()=>_v.ToString();public string ToString(string format,IFormatProvider formatProvider)=>_v.ToString(format,formatProvider);public override bool Equals(object obj)=>obj is StaticModIntm&&Equals(m);[MethodImpl(256)]public bool Equals(StaticModIntother)=>_v==other._v;public override int GetHashCode()=>_v.GetHashCode();}} namespace Kzrnm.Competitive.IO{using static Utf8Parser;using _R=ConsoleReader;using MI=System.Runtime.CompilerServices.MethodImplAttribute;public class ConsoleReader{internal const int BufSize=1<<12;internal readonly Stream input;internal readonly Encoding encoding;internal readonly byte[]buf;internal int pos;internal int len;[MI(256)]public ConsoleReader():this(Console.OpenStandardInput(),Console.InputEncoding,BufSize){}[MI(256)]public ConsoleReader(Stream input,Encoding encoding):this(input,encoding,BufSize){}[MI(256)]public ConsoleReader(Stream input,Encoding encoding,int bufferSize){this.input=input;this.encoding=encoding;buf=new byte[bufferSize];}[MI(256)]private void FillEntireNumber(){if((uint)pos>=(uint)buf.Length)FillNextBuffer();while(buf[pos]<=' ')if( ++pos>=len)FillNextBuffer();if(pos+21>=buf.Length&&buf[buf.Length-1]>' ')FillEntireNumberImpl();}private void FillEntireNumberImpl(){buf.AsSpan(pos,len-pos).CopyTo(buf);len-=pos;pos=0;var numberOfBytes=input.Read(buf,len,buf.Length-len);if(numberOfBytes==0)buf[len++]=10;else if(numberOfBytes+len=len)FillNextBuffer();return buf[pos++];}[MI(256)]public T Read(){if(typeof(T)==typeof(int))return(T)(object)Int();if(typeof(T)==typeof(uint))return(T)(object)UInt();if(typeof(T)==typeof(long))return(T)(object)Long();if(typeof(T)==typeof(ulong))return(T)(object)ULong();if(typeof(T)==typeof(double))return(T)(object)Double();if(typeof(T)==typeof(decimal))return(T)(object)Decimal();if(typeof(T)==typeof(char))return(T)(object)Char();if(typeof(T)==typeof(string))return(T)(object)Ascii();return Throw();}static T Throw()=>throw new NotSupportedException(typeof(T).Name);[MI(256)]public int Int(){FillEntireNumber();TryParse(buf.AsSpan(pos),out int v,out int bc);pos+=bc;return v;}[MI(256)]public uint UInt(){FillEntireNumber();TryParse(buf.AsSpan(pos),out uint v,out int bc);pos+=bc;return v;}[MI(256)]public long Long(){FillEntireNumber();TryParse(buf.AsSpan(pos),out long v,out int bc);pos+=bc;return v;}[MI(256)]public ulong ULong(){FillEntireNumber();TryParse(buf.AsSpan(pos),out ulong v,out int bc);pos+=bc;return v;}[MI(256)]public double Double(){FillEntireNumber();TryParse(buf.AsSpan(pos),out double v,out int bc);pos+=bc;return v;}[MI(256)]public decimal Decimal(){FillEntireNumber();TryParse(buf.AsSpan(pos),out decimal v,out int bc);pos+=bc;return v;}[MI(256)]public string String(){var sb=new List();;byte b;do b=ReadByte();while(b<=' ');do{sb.Add(b);b=ReadByte();}while(' '();byte b;do b=ReadByte();while(b<=' ');do{sb.Add(b);b=ReadByte();}while(b!='\n'&&b!='\r');return encoding.GetString(sb.ToArray());}[MI(256)]public char Char(){byte b;do b=ReadByte();while(b<=' ');return(char)b;}[MI(256)]public int Int0()=>Int()-1;[MI(256)]public uint UInt0()=>UInt()-1;[MI(256)]public long Long0()=>Long()-1;[MI(256)]public ulong ULong0()=>ULong()-1;[MI(256)]public static implicit operator int(_R cr)=>cr.Int();[MI(256)]public static implicit operator uint(_R cr)=>cr.UInt();[MI(256)]public static implicit operator long(_R cr)=>cr.Long();[MI(256)]public static implicit operator ulong(_R cr)=>cr.ULong();[MI(256)]public static implicit operator double(_R cr)=>cr.Double();[MI(256)]public static implicit operator decimal(_R cr)=>cr.Decimal();[MI(256)]public static implicit operator string(_R cr)=>cr.Ascii();public T[]Repeat(int count){var arr=new T[count];for(int i=0;i();return arr;}}} namespace Kzrnm.Competitive.IO{using _W=ConsoleWriter;using MI=System.Runtime.CompilerServices.MethodImplAttribute;public sealed partial class ConsoleWriter:IDisposable{private const int BufSize=1<<12;private readonly StreamWriter sw;public StreamWriter StreamWriter=>sw;public ConsoleWriter():this(Console.OpenStandardOutput(),Console.OutputEncoding){}public ConsoleWriter(Stream output,Encoding encoding):this(output,encoding,BufSize){}public ConsoleWriter(Stream output,Encoding encoding,int bufferSize){sw=new StreamWriter(output,encoding,bufferSize);}[MI(256)]public void Flush()=>sw.Flush();[MI(256)]public void Dispose()=>Flush();[MI(256)]public _W Write(T v){sw.Write(v.ToString());return this;}[MI(256)]public _W WriteLine(){sw.WriteLine();return this;}[MI(256)]public _W WriteLine(T v){sw.WriteLine(v.ToString());return this;}[MI(256)]public _W WriteLineJoin(IEnumerablecol)=>WriteMany(' ',col);[MI(256)]public _W WriteLineJoin((T1,T2)tuple)=>WriteLineJoin(tuple.Item1,tuple.Item2);[MI(256)]public _W WriteLineJoin((T1,T2,T3)tuple)=>WriteLineJoin(tuple.Item1,tuple.Item2,tuple.Item3);[MI(256)]public _W WriteLineJoin((T1,T2,T3,T4)tuple)=>WriteLineJoin(tuple.Item1,tuple.Item2,tuple.Item3,tuple.Item4);[MI(256)]public _W WriteLineJoin(TTuple tuple)where TTuple:System.Runtime.CompilerServices.ITuple{var col=new object[tuple.Length];for(int i=0;iWriteMany(' ',col);[MI(256)]public _W WriteLineJoin(T1 v1,T2 v2){sw.Write(v1.ToString());sw.Write(' ');sw.WriteLine(v2.ToString());return this;}[MI(256)]public _W WriteLineJoin(T1 v1,T2 v2,T3 v3){sw.Write(v1.ToString());sw.Write(' ');sw.Write(v2.ToString());sw.Write(' ');sw.WriteLine(v3.ToString());return this;}[MI(256)]public _W WriteLineJoin(T1 v1,T2 v2,T3 v3,T4 v4){sw.Write(v1.ToString());sw.Write(' ');sw.Write(v2.ToString());sw.Write(' ');sw.Write(v3.ToString());sw.Write(' ');sw.WriteLine(v4.ToString());return this;}[MI(256)]public _W WriteLines(IEnumerablecol)=>WriteMany('\n',col);[MI(256)]public _W WriteGrid(IEnumerable>cols){foreach(var col in cols)WriteLineJoin(col);return this;}[MI(256)]public _W WriteGrid(IEnumerabletuples)where TTuple:System.Runtime.CompilerServices.ITuple{foreach(var tup in tuples)WriteLineJoin(tup);return this;}[MI(256)]private _W WriteMany(char sep,IEnumerablecol){var en=col.GetEnumerator();if(!en.MoveNext())goto End;sw.Write(en.Current.ToString());while(en.MoveNext()){sw.Write(sep);sw.Write(en.Current.ToString());}End:sw.WriteLine();return this;}}} namespace Kzrnm.Competitive.IO{using MI=System.Runtime.CompilerServices.MethodImplAttribute;public partial class ConsoleWriter{[MI(256)]public ConsoleWriter WriteLine(ReadOnlySpanv){sw.WriteLine(v);return this;}[MI(256)]public ConsoleWriter WriteLineJoin(Spancol)=>WriteMany(' ',(ReadOnlySpan)col);[MI(256)]public ConsoleWriter WriteLineJoin(ReadOnlySpancol)=>WriteMany(' ',col);[MI(256)]public ConsoleWriter WriteLines(Spancol)=>WriteMany('\n',(ReadOnlySpan)col);[MI(256)]public ConsoleWriter WriteLines(ReadOnlySpancol)=>WriteMany('\n',col);[MI(256)]private ConsoleWriter WriteMany(char sep,ReadOnlySpancol){var en=col.GetEnumerator();if(!en.MoveNext())return this;sw.Write(en.Current.ToString());while(en.MoveNext()){sw.Write(sep);sw.Write(en.Current.ToString());}sw.WriteLine();return this;}}} namespace SourceExpander{public class Expander{[Conditional("EXP")]public static void Expand(string inputFilePath=null,string outputFilePath=null,bool ignoreAnyError=true){}public static string ExpandString(string inputFilePath=null,bool ignoreAnyError=true){return "";}}} #endregion Expanded by https://github.com/kzrnm/SourceExpander