#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

int n,m,sum;

int f[][],p=;

int main(){

    scanf("%d%d",&n,&m);

    f[][]=;

/*

    for(int i=1;i<=n;i++)

        for(int j=1;j<=m;j++)

            for(int k=0;k<i&&k<=j;k++)

                (f[i][j]+=f[i-1][j-k])%=p;

*/

    for (int i=;i<=n;i++){

        sum=;

        for (int j=;j<=m;j++){

            if (j>=i)sum=(sum-f[i-][j-i]+p)%p;

            (sum+=f[i-][j])%=p;

            f[i][j]=sum;

        }

    }

    printf("%d",f[n][m]);

    return ;

}