#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;

constexpr int P = 1000000007;

constexpr int N = 300, K = N * (N - 1) / 2;
int dp[K + 1];

int main() {
    int n, k;
    cin >> n >> k;

    dp[0] = 1;
    for (int i = 2; i <= n; i++) {
        int k1 = min(k, i * (i - 1) / 2);
        int64_t t = 0;
        for (int j = max(0, k1 - i + 1); j <= k1; j++) {
            t += dp[j];
        }
        t %= P;
        for (int j = k1; j >= 0; j--) {
            int s = t;
            t -= dp[j]; if (t < 0) t += P;
            if (j - i >= 0) {
                t += dp[j - i]; if (t >= P) t -= P;
            }
            dp[j] = s;
        }
    }

    int64_t r = 0;
    for (int j = 0; j <= k; j++) {
        r += dp[j];
    }
    r %= P;

    cout << r << endl;

    return 0;
}