代码如下

#include <bits/stdc++.h>

using namespace std;

int n, amount[3], price[3], total[3], minx = 10001;

int main()
{
    cin >> n;

    for (int i = 0; i < 3; i++)
    {
        cin >> amount[i] >> price[i];
    }

    for (int i = 0; i < 3; i++)
    {   
        int a;
        a = n / amount[i];
        if (n <= amount[i])
        {
            total[i] = price[i];
        }
        else
        {
            total[i] = (a + 1) * price[i];
        }
    }

    for (int i = 0; i < 3; i++)
    {
        minx = min(minx, total[i]);
    }

    cout << minx << endl;

    return 0;
}