func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, m, a, b, sum = 0, sum1 = 0;     cin >> n >> m >> a >> b;     sum = n / m;     sum1 = n - (sum * m);     if (sum * b < n * a) {       cout << min((sum * b + sum1 * a), ((sum + 1) * b));     }     if (sum * b >= n * a) {       cout << n * a;     }     return 0;   }   