using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
using System.Threading;
using System.Runtime.CompilerServices;
using System.Diagnostics;
//using nint=System.Int32;
static class Program{
	const long inf=long.MaxValue>>1;
	const int mod=998244353;//(int)1e9+7;
	static Sc sc=new Sc();
	static void Main(){
		Pt pt=new Pt(Solve);
		pt.Sm();
	}
	static void Solve(Pt pt) {
		var (n,m)=sc.Tp2<int>();
		var dp=new Mint[m+1,n+2];
		for(int i = 1;i <= m;i++) {dp[i,n]=1;}
		for(int i = 0;i <= n;i++) {dp[m,i]=1;}
		for(int i = m - 1;i >= 0;i--) {
			for(int j = n - 1;j >= 0;j--) {dp[i,j]=dp[i+1,j+1]/(n-j)+dp[i,j+1];}
		}
		pt.Wl(dp[0,0]-dp[0,1]);
	}
}
public struct Mint{
	const int mod=998244353;//(int)1e9+7;
	private long d;
	public Mint(long d){this.d=d;}
	public static implicit operator Mint(long d){return new Mint(d%mod);}
	public static explicit operator long(Mint d){return d.d;}
	public override string ToString(){return d.ToString();}
	public static Mint operator+(Mint a,long b){a.d=(mod+a.d+b%mod)%mod;return a;}
	public static Mint operator+(Mint a,Mint b){a.d=(a.d+b.d)%mod;return a;}
	public static Mint operator-(Mint a,long b){a.d=(mod+a.d-b%mod)%mod;return a;}
	public static Mint operator-(Mint a,Mint b){a.d=(mod+a.d-b.d)%mod;return a;}
	public static Mint operator*(Mint a,long b){a.d=b%mod*a.d%mod;return a;}
	public static Mint operator*(Mint a,Mint b){a.d=a.d*b.d%mod;return a;}
	public static Mint operator/(Mint a,long b){a.d=a.d*Mi(b)%mod;return a;}
	public static Mint operator/(Mint a,Mint b){a.d=a.d*Mi(b.d)%mod;return a;}
	public static bool operator==(Mint a,long b){return (long)a==b;}
	public static bool operator!=(Mint a,long b){return (long)a!=b;}
	public override bool Equals(object obj){return false;}
	public override int GetHashCode(){return 0;}
	public static long Mi(long a){
		a=(a+mod)%mod;
		long b=mod,u=1,v=0;
		while(b>0){
			long t=a/b;
			a-=t*b;(a,b)=(b,a);
			u-=t*v;(u,v)=(v,u);
		}
		u%=mod;
		if(u<0){u+=mod;}
		return u%mod;
	}
}
public class Pt{
	private StringBuilder sb=new StringBuilder();
	public Pt(Action<Pt> f){f(this);}
	public void W(int s){sb.Append(s);}
	public void W(long s){sb.Append(s);}
	public void W(double s){sb.Append(s);}
	public void W(decimal s){sb.Append(s);}
	public void W(char s){sb.Append(s);}
	public void W(string s){sb.Append(s);}
	public void W(object s){sb.Append(s);}
	public void W(string f,int s){sb.Append(s.ToString(f));}
	public void W(string f,long s){sb.Append(s.ToString(f));}
	public void W(string f,double s){sb.Append(s.ToString(f));}
	public void W(string f,decimal s){sb.Append(s.ToString(f));}
	public void Wl(int s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(long s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(double s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(decimal s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(char s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(string s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(object s){sb.Append(s).Append(Environment.NewLine);}
	public void Wl(string f,int s){sb.Append(s.ToString(f)).Append(Environment.NewLine);}
	public void Wl(string f,long s){sb.Append(s.ToString(f)).Append(Environment.NewLine);}
	public void Wl(string f,double s){sb.Append(s.ToString(f)).Append(Environment.NewLine);}
	public void Wl(string f,decimal s){sb.Append(s.ToString(f)).Append(Environment.NewLine);}
	public void Wl(int[] s){sb.Append(string.Join(" ",s)).Append(Environment.NewLine);}
	public void Wl(long[] s){sb.Append(string.Join(" ",s)).Append(Environment.NewLine);}
	public void Wl(double[] s){sb.Append(string.Join(" ",s)).Append(Environment.NewLine);}
	public void Wl(string[] s){sb.Append(string.Join(" ",s)).Append(Environment.NewLine);}
	public void Wl(object[] s){sb.Append(string.Join(" ",s)).Append(Environment.NewLine);}
	public void Wl(){sb.Append(Environment.NewLine);}
	public void Sm(){Console.Write(sb);}
	public static bool operator==(Pt a,Pt b){return a.sb.ToString()==b.sb.ToString();}
	public static bool operator!=(Pt a,Pt b){return a.sb.ToString()!=b.sb.ToString();}
	public override bool Equals(object obj){return false;}
	public override int GetHashCode(){return 0;}
}
public class Sc{
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected virtual string Rl(){return Console.ReadLine();}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected virtual string[] Sp(string st){return st.Split();}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	private T Ct<T>(string s){return (T)Convert.ChangeType(s,typeof(T));}
	public virtual int I{get{return int.Parse(Rl());}}
	public virtual long L{get{return long.Parse(Rl());}}
	public virtual double D{get{return double.Parse(Rl());}}
	public virtual string S{get{return Rl();}}
	public int[] Ia{get{return Array.ConvertAll(Sp(Rl()),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Sp(Rl()),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Sp(Rl()),double.Parse);}}
	public string[] Sa{get{return Sp(Rl());}}
	public object[] Oa{get{return Sp(Rl());}}
	public int[] Ia2{get{return Array.ConvertAll(Sp("0 "+Rl()+" 0"),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll(Sp(a+Rl()+b),int.Parse);}
	public int[] Ia3(int a){return Array.ConvertAll(Sp(Rl()+" "+a.ToString()),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(Sp("0 "+Rl()+" 0"),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll(Sp(a+Rl()+b),long.Parse);}
	public long[] La3(int a){return Array.ConvertAll(Sp(Rl()+" "+a.ToString()),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(Sp("0 "+Rl()+" 0"),double.Parse);}}
	public double[] Da3(string a,string b){return Array.ConvertAll(Sp(a+Rl()+b),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Sp(Rl()));}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Sp(Rl()));}return a;}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T,T) Tp2<T>(){var s=Sp(Rl());return (Ct<T>(s[0]),Ct<T>(s[1]));}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T,T,T) Tp3<T>(){var s=Sp(Rl());return (Ct<T>(s[0]),Ct<T>(s[1]),Ct<T>(s[2]));}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T,T,T,T) Tp4<T>(){var s=Sp(Rl());return (Ct<T>(s[0]),Ct<T>(s[1]),Ct<T>(s[2]),Ct<T>(s[3]));}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T,T,T,T,T) Tp5<T>(){var s=Sp(Rl());return (Ct<T>(s[0]),Ct<T>(s[1]),Ct<T>(s[2]),Ct<T>(s[3]),Ct<T>(s[4]));}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T,T,T,T,T,T) Tp6<T>(){var s=Sp(Rl());return (Ct<T>(s[0]),Ct<T>(s[1]),Ct<T>(s[2]),Ct<T>(s[3]),Ct<T>(s[4]),Ct<T>(s[5]));}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T1,T2) Tp2<T1,T2>(){var s=Sp(Rl());return (Ct<T1>(s[0]),Ct<T2>(s[1]));}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	public (T1,T1,T2) Tp3<T1,T2>(){var s=Sp(Rl());return (Ct<T1>(s[0]),Ct<T1>(s[1]),Ct<T2>(s[2]));}
}
public class Scr:Sc{
	private List<string> li=new List<string>();
	private int l=0;
	private bool bo=false;
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected override string Rl(){
		if(bo){return li[l++%li.Count];}
		li.Add(Console.ReadLine());
		return li[li.Count-1];
	}
	public void Again(){bo=true;}
}
public class Sc2:Sc{
	private string[] sps=new string[]{" ","　","\t"};
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	protected override string[] Sp(string st){return st.Split(sps,StringSplitOptions.RemoveEmptyEntries);}
	public override int I{get{return int.Parse(Sp(Rl())[0]);}}
	public override long L{get{return long.Parse(Sp(Rl())[0]);}}
	public override double D{get{return double.Parse(Sp(Rl())[0]);}}
	public override string S{get{return Sp(Rl())[0];}}
}
public class Sct:Sc{
	private List<string> li=new List<string>();
	private int l=0;
	public void Add(int s){li.Add(s.ToString());}
	public void Add(long s){li.Add(s.ToString());}
	public void Add(double s){li.Add(s.ToString());}
	public void Add(string s){li.Add(s.ToString());}
	public void Add(object s){li.Add(s.ToString());}
	public void Add(int[] s){li.Add(string.Join(" ",s));}
	public void Add(long[] s){li.Add(string.Join(" ",s));}
	public void Add(double[] s){li.Add(string.Join(" ",s));}
	public void Add(string[] s){li.Add(string.Join(" ",s));}
	public void Add(object[] s){li.Add(string.Join(" ",s));}
	protected override string Rl(){return li[l++];}
	public void Clear(){li.Clear();l=0;}
	public void Again(){l=0;}
	public void Pf(){Console.WriteLine(string.Join("\n",li));}
}