#include<bits/stdc++.h>
using namespace std;
int main(){int c,d=999990,i,a[4],b[4],n;
	cin>>n;
	for(i=1;i<4;i++){cin>>a[i]>>b[i];
	if(n%a[i]!=0) c=(n/a[i]+1)*b[i];
	else c=n/a[i]*b[i];
	if(c<d) d=c;}
	cout<<d;
return 0;	}