#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    scanf("%d", &n);

    int a, b, c, d, e, f, g, h, i;
    scanf("%d %d %d %d %d %d", &a, &b, &d, &e, &g, &h);

    //第一组
    c = (n % a == 0 ? n / a : n / a + 1) * b;
    //第二组
    f = (n % d == 0 ? n / d : n / d + 1) * e;
    //第三组
    i = (n % g == 0 ? n / g : n / g + 1) * h;

    //取最小值时的办法
    printf("%d\n", min({c, f, i}));

    return 0;
}