#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using LP = pair<ll, ll>;
template <class S, class T>
istream& operator>>(istream& is, pair<S, T>& p) {
  return is >> p.first >> p.second;
}
template <class S, class T>
ostream& operator<<(ostream& os, const pair<S, T>& p) {
  return os << '{' << p.first << "," << p.second << '}';
}
template <class T>
istream& operator>>(istream& is, vector<T>& v) {
  for (T& t : v) {
    is >> t;
  }
  return is;
}
template <class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
  os << '[';
  for (int i = 0; i < (v.size()); ++i)
    os << v[i] << (i == v.size() - 1 ? ']' : ',');
  return os;
}
void Yes(bool b) { cout << (b ? "Yes" : "No") << endl; }
void YES(bool b) { cout << (b ? "YES" : "NO") << endl; }
template <class T>
bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
const int inf = 1001001001;
const ll linf = 1001001001001001001;
const int mod = 1000000007;
struct mint {
  ll x;
  mint(ll 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++() { return *this += mint(1); }
  mint& operator-=(const mint& a) {
    if ((x += mod - a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator--() { return *this -= mint(1); }
  mint& operator*=(const mint& a) {
    (x *= a.x) %= mod;
    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(ll t) const {
    mint res = mint(1), a(*this);
    while (t > 0) {
      if (t & 1) res *= a;
      t >>= 1;
      a *= a;
    }
    return res;
  }
  mint inv() const { return pow(mod - 2); }
  mint& operator/=(const mint& a) { return *this *= a.inv(); }
  mint operator/(const mint& a) const {
    mint res(*this);
    return res /= a;
  }
};
ostream& operator<<(ostream& os, const mint& m) { return os << m.x; }
mint dp[3100][3100];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int n, s;
  cin >> n >> s;
  vector<int> a(n);
  cin >> a;
  for (int i = 0; i < (n); ++i) dp[i][0] = 1;
  mint ans;
  for (int i = 0; i < (n); ++i) {
    for (int j = 0; j < (s + 1); ++j) {
      if (j + a[i] <= s) dp[i + 1][j + a[i]] += dp[i][j];
      dp[i + 1][j] += dp[i][j];
    }
    ans += dp[i + 1][s];
  }
  cout << ans << endl;
}
