#include<bits/stdc++.h>
using namespace std;
int a[4],b,c,d=100000010,e[4];
int main(){
	cin>>b;
	for(int i=0;i<=2;i++){
		cin>>a[i]>>e[i];
		c=ceil((double)b/a[i])*e[i];
		if(c<d){
			d=c;
		}
	}
	cout<<d;
	return 0;
}