#include <iostream>
using namespace std;
int n, a[4], b[4], mi = 99999;
int main(){
    cin >> n;
    for(int i = 1; i <= 3; i++) {
        cin >> a[i] >> b[i];
    }
    for(int i = 1; i <= 3; i++) {
        if(n % a[i] == 0 && n / a[i] * b[i] < mi) {
            mi = b[i];
        }else if(n % a[i] != 0 && (n / a[i] + 1) * b[i] < mi){
            mi = (n / a[i] + 1) * b[i];
        }
    }
    cout << mi << endl;
    return 0;
}