10. Profit

#include <iostream>

using namespace std;

int main() {

    int oneBGNCoinCount, twoBGNCoinCount, fiveBGNCoinCount, sum;
    cin >> oneBGNCoinCount >> twoBGNCoinCount >> fiveBGNCoinCount >> sum;

    for (int i = 0; i <= oneBGNCoinCount; i++) {
        for (int j = 0; j <= twoBGNCoinCount; j++) {
            for (int k = 0; k <= fiveBGNCoinCount; k++) {
                if (i * 1 + j * 2 + k * 5 == sum) {
                    cout << i << " * 1 lv. + " << j << " * 2 lv. + " << k << " * 5 lv. = " << sum << " lv.\n";
                }
            }
        }
    }
    return 0;
}