#include<iostream>
#include<cmath>
using namespace std;
long long q,w,e,r,t,y,u,i,o,p,s,d,f,g,h,j,k,l,m,n,v,x,z,c;
double a,b;
int main()
{
    s=999999999;
    cin>>n;
    for(i=1;i<=3;i++)
    {
        cin>>a>>b;
        k=ceil(n*1.0/a)*b;
        if(k<s)
        s=k;
    }
    cout<<s;
    return 0;
}