#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  long long n, m;
  cin >> n >> m;
  long long arr[n];
  long long sum = 0;
  for (long long i = 0; i < n; i++) {
    cin >> arr[i];
    sum += arr[i];
  }
  sum += (n - 1);
  if (sum == m)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
