#include <bits/stdc++.h>
using namespace std;
const long long INF = 1LL << 60;
long long N, S;
vector<long long> A;
const int mod = 1e9 + 7;
struct mint {
  long long x;
  mint(long long x = 0) : x((x % mod + mod) % mod) {}
  mint operator-() const { return mint(-x); }
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod - a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint a) const { return mint(*this) += a; }
  mint operator-(const mint a) const { return mint(*this) -= a; }
  mint operator*(const mint a) const { return mint(*this) *= a; }
  mint pow(long long t) const {
    if (!t) return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1) a *= *this;
    return a;
  }
  mint inv() const { return pow(mod - 2); }
  mint& operator/=(const mint a) { return *this *= a.inv(); }
  mint operator/(const mint a) const { return mint(*this) /= a; }
};
istream& operator>>(istream& is, const mint& a) { return is >> a.x; }
ostream& operator<<(ostream& os, const mint& a) { return os << a.x; }
int main() {
  cin >> N >> S;
  A.resize(N);
  for (int i = 0; i < (N); ++i) cin >> A[i];
  vector<mint> q(S + 1);
  mint ans = 0;
  for (int i = 0; i < (N); ++i) {
    q[0] += 1;
    vector<mint> q2(S + 1);
    for (int j = 0; j < (S + 1); ++j) {
      q2[j] += q[j];
      if (j + A[i] <= S) q2[j + A[i]] += q[j];
    }
    q = q2;
    ans += q[S];
  }
  cout << ans << endl;
}
