#include<bits/stdc++.h>
using namespace std;
int main(){
	int b,i=0,a1,c1,a2,c2,a3,c3;
	cin>>b>>a1>>c1>>a2>>c2>>a3>>c3;
	
	if(b%a1!=0) a1=b/a1,a1+=c1,c1*=a1;
	else a1=b/a1; c1*=a1;
	if(b%a2!=0) a2=b/a2,a2+=c2,c2*=a2;
	else a2=b/a2; c2*=a2;
	if(b%a3!=0) a3=b/a3,a3+=c3,c3*=a3;
	else a3=b/a3,c3*=a3;
	
	cout<<min(c1,min(c2,c3));
return 0;
}