func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     int arr[5] = {0};     for (int i = 0; i < n; ++i) {       int tmp;       cin >> tmp;       arr[tmp]++;     }     int ret = arr[4];     ret += min(arr[1], arr[3]);     ret += arr[2] / 2;     if (arr[3] > arr[1]) {       ret += arr[3] - arr[1];       ret += (arr[2] % 2) ? 1 : 0;     } else {       int tmp = arr[1] - arr[3];       ret += tmp / 4;       if (arr[2] % 2) {         if (tmp % 4 <= 2)           ret += 1;         else           ret += 2;       } else {         ret += (tmp % 4) ? 1 : 0;       }     }     cout << ret << endl;     return 0;   }   