func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   int a[1005];   int main() {     cin >> n;     int x;     int ans = 0;     if (n == 1) {       cin >> x;       if (x)         cout <<  YES  << endl;       else         cout <<  NO  << endl;       return 0;     }     for (int i = 0; i < n; i++) {       cin >> x;       ans += x;     }     if (ans == n - 1)       cout <<  YES  << endl;     else       cout <<  NO  << endl;     return 0;   }   