#include<stdio.h>
int main()
{
    int n,a,b,i,k,s,min=100000000;
    scanf("%d\n",&n);
    for(i=0;i<3;i++)
    {
        scanf("%d %d",&a,&b);
        k=n/a;
        if(n%a==0) s=k*b;
        else       s=(k+1)*b;
        if(s<min)
        min=s;
    }
     printf("%d",s);
     return 0;
}