func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     vector<int> v(n);     for (int i = 0; i != n; ++i) {       cin >> v[i];       v[i] -= (n - i);     }     sort(v.begin(), v.end());     for (int i = 0; i != n - 1; ++i) {       if (v[i] + 1 > v[i + 1]) {         cout <<  :( n ;         return 0;       }     }     for (int i = 0; i != n; ++i) {       cout << v[i] + (n - i) <<    ;     }     return 0;   }   