代码如下：

#include <iostream>
using namespace std;

int main(){
    long price[3], contain[3], sumprice[3];
    long need, min = need*(price[0]+price[1]+price[2]);
    cin >> need >> contain[0] >> price[0] >> contain[1] >> price[1] >> contain[2] >> price[2];
    for (int i = 0; i <= 2; i++){
        for (int x = 1; x++;){
            sumprice[i] = x*price[i];
            if (x*contain[i] >= need) break;
        }
        if (sumprice[i] < min){
            min = sumprice[i];
        }
    }
    cout << min;
    return 0;
}