#include<iostream>
#include<cmath>
using namespace std;
int main()
{
	float n,a,b,c,d,e,f,g,h,i;
	cin>>n>>a>>b>>c>>d>>e>>f;
	g=ceil(float(n/a))*b;
	h=ceil(float(n/c))*d;
	i=ceil(float(n/e))*f;
	cout<<min(min(g,h),i);
    return 0;
}