#include<bits/stdc++.h> 
using namespace std;
int a,b,c,d,e,f,g,h,i,j; 
int main(){
	cin>>a>>b>>c>>d>>e>>f>>g;
    if(a%b==0)h=a/b;
    else h=a/b+1;
    h*=c;
    if(a%d==0)i=a/d;
    else i=a/d+1;
    i*=e;
    if(a%f==0)j=a/f;
    else j=a/f+1;
    j*=g;
    cout<<min(h,min(i,j));
    return 0;
}