#include<cstdio>
#include<iostream>
#include<fstream>
#include<algorithm>
using namespace std;
struct buy
{
int pencil;
long long money;
};
buy x[3];
int main()
{
//freopen("pencil.in","r",stdin);
//freopen("pencil.out","r",stdout);
int n,a,b[4];
cin>>n;
for(int i=0;i<3;i++)
cin>>x[i].pencil>>x[i].money;
for(int i=0;i<3;i++)
{
a=n/x[i].pencil;
if(n%(x[i].pencil)>0) a++;
b[i]=(x[i].money)*a;
}
sort(b,b+3);
cout<<b[0]<<endl;
return 0;
}

very easy!