#include <bits/stdc++.h>
using namespace std;
const long long N = 30, mod = 1000000007;
long long n, m, ans, a[N];
inline long long read() {
  long long x = 0, tmp = 1;
  char ch = getchar();
  while (!isdigit(ch)) {
    if (ch == '-') tmp = -1;
    ch = getchar();
  }
  while (isdigit(ch)) {
    x = (x << 3) + (x << 1) + (ch ^ 48);
    ch = getchar();
  }
  return tmp * x;
}
long long ksm(long long x, long long y) {
  if (y == 0) return 1;
  long long t = ksm(x, y >> 1) % mod;
  t = t * t % mod;
  if (y & 1) t = t * x % mod;
  return t;
}
inline long long inv(long long x) { return ksm(x, mod - 2); }
inline long long C(long long n, long long m) {
  if (n < m) return 0;
  long long x = 1, y = 1;
  for (long long i = 1; i <= m; i++) {
    x = x * (n - i + 1) % mod;
    y = y * i % mod;
  }
  return x * inv(y) % mod;
}
long long lucas(long long n, long long m) {
  if (m == 0) return 1;
  return C(n % mod, m % mod) * lucas(n / mod, m / mod) % mod;
}
int main() {
  n = read();
  m = read();
  for (long long i = 1; i <= n; i++) a[i] = read();
  for (long long i = 0; i < (1 << n); i++) {
    long long cnt = m, tmp = 1;
    for (long long j = 1; j <= n; j++) {
      if (i & (1 << (j - 1))) {
        cnt -= a[j] + 1;
        tmp = -tmp;
      }
    }
    if (cnt < 0) continue;
    ans = (ans + mod + lucas(cnt + n - 1, n - 1) * tmp) % mod;
  }
  cout << ans << endl;
  return 0;
}
