#include <bits/stdc++.h>
using namespace std;
double n;
double minn=1e8+100,z,x;
int main(){
	cin>>n;
	for(int i=0;i<3;i++){
		cin>>z>>x;
		minn=min(x*ceil(n/z*1.0),minn);
	}
	cout<<minn;
	return 0;
}