#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
const int inf = 0x3f3f3f3f;
int main() {
  int n;
  long long len = 0, x;
  scanf("%d %I64d", &n, &x);
  for (int i = 0, num; i < n; i++) {
    scanf("%d", &num);
    len += num;
    if (i != n - 1) len += 1;
  }
  printf("%s\n", len == x ? "YES" : "NO");
  return 0;
}
