#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
long long pow_[20];
long long binpow(long long a, long long n) {
  long long res = 1;
  while (n) {
    if (n % 2 == 1) {
      res = (a * res) % mod;
    }
    a = (a * a) % mod;
    n /= 2;
  }
  return res;
}
long long C(long long n, long long k) {
  long long res = 1;
  n = n % mod;
  for (long long i = n; i >= n - k + 1; i--) {
    res = (res * i) % mod;
  }
  for (long long i = 1; i <= k; i++) {
    res = (res * pow_[i]) % mod;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie();
  cout.tie();
  for (long long i = 1; i <= 19; i++) {
    pow_[i] = binpow(i, mod - 2);
  }
  long long n, s;
  cin >> n >> s;
  vector<long long> f(n);
  for (long long i = 0; i < n; i++) cin >> f[i];
  long long res = 0;
  for (long long mask = 0; mask < (1 << n); mask++) {
    long long t = 0;
    for (long long i = 0; i < n; i++) {
      if (mask & (1 << i)) t++;
    }
    long long cur;
    if (t % 2 == 0)
      cur = 1;
    else
      cur = -1;
    long long sum = 0;
    for (long long i = 0; i < n; i++) {
      if (mask & (1 << i)) sum += (f[i] + 1);
    }
    if (s - sum + n - 1 < n - 1) continue;
    cur = (cur * C(s - sum + n - 1, n - 1) + mod) % mod;
    res = (res + cur) % mod;
  }
  cout << res << '\n';
  return 0;
}
