#include <bits/stdc++.h>
using namespace std;
long long a, r, b, c, k, s, n, t, j, max1 = -9999999, min1 = 9999999, i, l, w,
                                     h, m[1000000];
pair<long long, long long> x[11111];
string q, p[101];
char e;
double d, v = 9999999999;
int main() {
  cin >> n >> b;
  t = n;
  while (n--) {
    cin >> a;
    b = b - a;
  }
  if (b == t - 1) {
    cout << "YES";
  } else
    cout << "NO";
}
