#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    double A,a;
    cin>>A>>a;
    double B,b;
    cin>>B>>b;
    double C,c;
    cin>>C>>c;
    double l,m,q;
    l=ceil(n/A)*a;
    m=ceil(n/B)*b;
    q=ceil(n/C)*c;
    double k;
    k=min(min(l,m),q);
    cout<<k<<endl;
    return 0;
}