#include <iostream>
#include <cstdio>

using namespace std;

int n,s;
int p;
int dp[33000];

int main()
{
    freopen("1-sir.in","r",stdin);
    freopen("1-sir.out","w",stdout);

    scanf("%d%d", &n,&s);
    p = (n*(n-1)/2 - s)/2;
    dp[0]=1;
    for(int i = 1; i<=min(p,n-1); ++i){
        for(int j = 0; j < i; ++j)
            dp[i+j]+=dp[j];
    }

    cout<<dp[p];

    return 0;
}