#include<bits/stdc++.h>
using namespace std;
int main () {
    int n,n1,n2,n3,p1,p2,p3,t1,t2,t3,total;
    cin>>n>>n1>>p1>>n2>>p2>>n3>>p3;
    t1 =  (n%n1==0)?  n/n1*p1 : (n/n1+1)*p1;
    t2 =  (n%n2==0)?  n/n2*p2 : (n/n2+1)*p2;
    t3 =  (n%n3==0)?  n/n3*p3 : (n/n3+1)*p3;
    total=t1;
    if(t2<total)total=t2;
    if(t3<total)total=t3;
    cout<<total<<endl;
}