#include <bits/stdc++.h>
using namespace std;
template <typename T>
void DEBUG(T e) {
  if (true == false) return;
  std::cout << e << " ";
}
template <typename T>
void DEBUG(const std::vector<T> &v) {
  if (true == false) return;
  for (const auto &e : v) {
    std::cout << e << " ";
  }
  std::cout << std::endl;
}
template <typename T>
void DEBUG(const std::vector<std::vector<T>> &vv) {
  if (true == false) return;
  for (const auto &v : vv) {
    DEBUG(v);
  }
}
template <class T, class... Ts>
void DEBUG(T d, Ts... e) {
  if (true == false) return;
  DEBUG(d);
  DEBUG(e...);
}
template <class T>
void corner(bool flg, T hoge) {
  if (flg) {
    cout << hoge << endl;
    abort();
  }
}
template <typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {
  return a < b && (a = b, true);
}
template <typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {
  return a > b && (a = b, true);
}
struct mint {
  long long x;
  mint(long long x = 0) : x((x % 1000000007 + 1000000007) % 1000000007) {}
  mint &operator+=(const mint a) {
    if ((x += a.x) >= 1000000007) x -= 1000000007;
    return *this;
  }
  mint &operator-=(const mint a) {
    if ((x += 1000000007 - a.x) >= 1000000007) x -= 1000000007;
    return *this;
  }
  mint &operator*=(const mint a) {
    (x *= a.x) %= 1000000007;
    return *this;
  }
  mint operator+(const mint a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint a) const {
    mint res(*this);
    return res -= a;
  }
  mint operator*(const mint a) const {
    mint res(*this);
    return res *= 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(1000000007 - 2); }
  mint &operator/=(const mint a) { return (*this) *= a.inv(); }
  mint operator/(const mint a) const {
    mint res(*this);
    return res /= a;
  }
};
const long long MAX = 510000;
long long fac[MAX], finv[MAX], inv[MAX];
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (long long i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % 1000000007;
    inv[i] = 1000000007 - inv[1000000007 % i] * (1000000007 / i) % 1000000007;
    finv[i] = finv[i - 1] * inv[i] % 1000000007;
  }
}
long long COM(long long n, long long k) {
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * (finv[k] * finv[n - k] % 1000000007) % 1000000007;
}
long long PERM(long long n, long long k) {
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * (finv[n - k] % 1000000007) % 1000000007;
}
long long MCOM(long long n, long long k) { return COM(n + k - 1, k); }
void solve(void) {
  long long n, s;
  cin >> n >> s;
  vector<long long> vec(n, 0);
  for (long long i = 0; i < n; i++) {
    cin >> vec[i];
  }
  mint res = 0;
  vector<mint> dp(s + 1);
  for (long long i = 0; i < n; i++) {
    dp[0] += 1;
    vector<mint> q2(s + 1);
    for (long long j = 0; j < s + 1; j++) {
      q2[j] += dp[j];
      if (j + vec[i] <= s) q2[j + vec[i]] += dp[j];
    }
    dp = q2;
    res += dp[s];
  }
  cout << res.x << endl;
}
int32_t main(int32_t argc, const char *argv[]) {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  std::cout << std::fixed;
  std::cout << std::setprecision(11);
  solve();
  return 0;
}
