#include 
#include 
#include 
#include 
using namespace std;
int n,k;
const int mod = 1e9 + 7;
int a[105];
int memo[100005];

int main() {
    cin >> n >> k;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    memset(memo,0,sizeof(memo));
    memo[0] = 1; // memo[i] - broj na nacini da stigneme so i candies
    for(int at = 0; at < n; at++) {
        for(int chocolates_left = k; chocolates_left >= 0; chocolates_left--) {
            int start = chocolates_left + 1;
            int end = chocolates_left + min(a[at], k - chocolates_left);
            for(int j = start; j <= end; j++) {
                    memo[j] += memo[chocolates_left];
                    memo[j] %= mod;
            }
        }
    }
    
        cout << memo[k] << endl;
    return 0;
}
// min(1, )