#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 1e5 + 5;


int n, w;
int a[105];
ll dp[N], prfx[2][N];


ll pfx(int u, int v, int x)
{
    return ((prfx[x][v + 1] % MOD) - (prfx[x][u] % MOD) + MOD) % MOD;
}


int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    cin >> n >> w;

    for (int i = 1; i <= n; i++) cin >> a[i];

    memset(dp, 0, sizeof(dp));
    for (int i = 1; i <= w + 1; i++) prfx[0][i] = 1;
    prfx[0][0] = 0; prfx[1][0] = 0; prfx[1][1] = 1;
    dp[0] = 1;

    for (int i = 1; i <= n ; i++)
    {
        int y, x; y = i % 2; x = 1 - y;
        for (int j = 1; j <= w; j++)
        {
            dp[j] = pfx(max(0, j - a[i]), j, x);
            prfx[y][j + 1] = ((prfx[y][j] % MOD) + dp[j]) % MOD;
        }
    }

    cout << dp[w];

    return 0;
}