#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e4 + 5;
using LL = int64_t;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  LL x, temp, sum = 0;
  cin >> n >> x;
  for (int i = 1; i <= n; i++) {
    cin >> temp;
    if (i != 1) temp++;
    sum += temp;
  }
  if (sum == x)
    cout << "YES\n";
  else
    cout << "NO\n";
  return 0;
}
