#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,qian[3],shu[3],jia[3];
	cin>>n;
	for(int i=0;i<3;i++)
	cin>>shu[i]>>qian[i];
	for(int i=0;i<3;i++)
		if(n%shu[i]==0)jia[i]=n/shu[i]*qian[i];
		else jia[i]=(n/shu[i]+1)*qian[i];
	cout<<min(min(jia[0],jia[1]),jia[2]);
}