func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long n;     cin >> n;     int cnt = 0, val;     for (int k = 0; k < n; k++) {       cin >> val;       cnt += val;     }     if (n == 1 && val == 1)       cout <<  YES ;     else if (cnt == n - 1 && n != 1)       cout <<  YES ;     else       cout <<  NO ;     return 0;   }   