#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x;
  cin >> n >> x;
  int s = 0;
  for (int i = 0; i < n; i++) {
    int m;
    cin >> m;
    s += m + 1;
  }
  if (x == s - 1)
    cout << "YES";
  else
    cout << "NO";
  cout << endl;
  return 0;
}
