#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = 1e3+10,mod = 998244353;
typedef long long LL;
LL f[N][N];
LL sum[N];
int main(){
 int n,m;
 scanf("%d%d",&n,&m);
 f[1][0]=1;
 for(int i=2;i<=n;i++){
  sum[0]=f[i-1][0];
  for(int j=0;j<=m;j++){
   sum[j]=(sum[j-1]+f[i-1][j])%mod;
  }
  for(int j=0;j<=m;j++){
   int last=j-(i-1)-1;
   f[i][j]+=sum[j];
   if(last>=0)f[i][j]=(f[i][j]-sum[last]+mod)%mod;
   f[i][j]%=mod;
  }
  
 }
 cout<<f[n][m];
 return 0;
}