#include <bits/stdc++.h>
using namespace std;
const int inf = INT_MAX / 2;
const long long infl = 1LL << 60;
template <class T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
template <int MOD>
struct ModInt {
  static const int Mod = MOD;
  unsigned x;
  ModInt() : x(0) {}
  ModInt(signed sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
  ModInt(signed long long sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
  int get() const { return (int)x; }
  ModInt &operator+=(ModInt that) {
    if ((x += that.x) >= MOD) x -= MOD;
    return *this;
  }
  ModInt &operator-=(ModInt that) {
    if ((x += MOD - that.x) >= MOD) x -= MOD;
    return *this;
  }
  ModInt &operator*=(ModInt that) {
    x = (unsigned long long)x * that.x % MOD;
    return *this;
  }
  ModInt &operator/=(ModInt that) { return *this *= that.inverse(); }
  ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
  ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
  ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
  ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
  ModInt inverse() const {
    long long a = x, b = MOD, u = 1, v = 0;
    while (b) {
      long long t = a / b;
      a -= t * b;
      std::swap(a, b);
      u -= t * v;
      std::swap(u, v);
    }
    return ModInt(u);
  }
  bool operator==(ModInt that) const { return x == that.x; }
  bool operator!=(ModInt that) const { return x != that.x; }
  ModInt operator-() const {
    ModInt t;
    t.x = x == 0 ? 0 : Mod - x;
    return t;
  }
};
template <int MOD>
ostream &operator<<(ostream &st, const ModInt<MOD> a) {
  st << a.get();
  return st;
};
template <int MOD>
ModInt<MOD> operator^(ModInt<MOD> a, unsigned long long k) {
  ModInt<MOD> r = 1;
  while (k) {
    if (k & 1) r *= a;
    a *= a;
    k >>= 1;
  }
  return r;
}
template <class V>
struct BIT {
  BIT() {}
  int NV;
  vector<V> bit;
  BIT(int n) { init(n); }
  void init(int n) {
    NV = 1;
    while (NV < n) NV *= 2;
    bit.resize(NV);
    clear();
  }
  V operator[](int e) {
    V s = 0;
    e++;
    while (e) s += bit[e - 1], e -= e & -e;
    return s;
  }
  void add(int e, V v) {
    e++;
    while (e <= NV) bit[e - 1] += v, e += e & -e;
  }
  int lower_bound(V val) {
    V tv = 0;
    int i, ent = 0;
    for (i = NV - 1; i >= 0; i--)
      if (tv + bit[ent + (1 << i) - 1] <= val)
        tv += bit[ent + (1 << i) - 1], ent += (1 << i);
    return ent;
  }
  V get(int L, int R) {
    assert(0 <= L);
    assert(R <= NV);
    assert(L <= R);
    V res = 0;
    if (R) res += operator[](R - 1);
    if (L) res -= operator[](L - 1);
    return res;
  }
  void clear() {
    for (int i = 0; i < NV; i++) bit[i] = 0;
  }
};
int N, K, A[101];
BIT<ModInt<1000000007> > dp[101];
int main() {
  cin >> N >> K;
  for (int i = 0; i < N; i++) cin >> A[i];
  for (int i = 0; i < N + 1; i++) dp[i].init(K + 1);
  dp[0].add(1, 1);
  for (int i = 1; i < N + 1; i++) {
    for (int j = 1; j < K + 2; j++) {
      dp[i].add(j, dp[i - 1].get(max(1, j - A[i - 1]), j));
    }
  }
  cout << dp[N].get(K + 1, K + 2) << endl;
}
