#include<bits/stdc++.h>
using namespace std;
int main(){
	double a, b, c, d, e, f, g, A, B, C, D, minn = 0;
    cin >> a;
	cin >> b >> c;
	cin >> e >> d;
	cin >> g >> f;
	A = ceil(a / b);
	B = ceil(a / e);
	C = ceil(a / g);
	minn = min(min(A * c, B * d), C * f);
	cout << minn;
	return 0;
}