#include <bits/stdc++.h>
using namespace std;
const int Mod = 1e9 + 7;
int n, inv;
long long m;
long long A[30];
inline int Qpow(int a, int b) {
  int ans = 1;
  while (b) {
    if (b & 1) ans = (long long)ans * a % Mod;
    b >>= 1;
    a = (long long)a * a % Mod;
  }
  return ans;
}
inline int C(long long a) {
  if (a < (n - 1)) return 0;
  long long res = 1;
  for (int i = 0; i < n - 1; i++) res = res * ((a - i) % Mod) % Mod;
  return res * inv % Mod;
}
inline void Init() {
  cin >> n >> m;
  inv = 1;
  for (int i = 2; i < n; i++) inv = (long long)inv * i % Mod;
  inv = Qpow(inv, Mod - 2);
  for (int i = 1; i <= n; i++) cin >> A[i];
}
inline void Work() {
  int res = 0;
  for (int i = 0; i < (1 << n); i++) {
    long long a = n + m - 1;
    int flag = 1;
    for (int j = 0; j < n; j++) {
      if ((i >> j) & 1) {
        flag *= -1;
        a -= A[j + 1] + 1;
      }
    }
    res = ((long long)res + (long long)flag * C(a) % Mod) % Mod;
  }
  cout << (res + Mod) % Mod << endl;
}
int main() {
  Init();
  Work();
  return 0;
}
