#include<bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n;
    int a[3], b[3];
    int pay[3];
    memset(pay, 0, 3);
    for (int i = 0; i < 3; i++) {
        cin >> a[i] >> b[i];
        pay[i] = ceil(n / a[i]) * b[i];
    }
    sort(pay, pay + 3);
    cout << pay[0] << endl;
    return 0;
}