#include<stdio.h>
#include<math.h>
int main()
{
    int n,m,p,i,sum,cost,min;
    min=999999;
    scanf("%d",&n);
    for(i=0;i<3;i++)
    {
        scanf("%d%d",&m,&p);
        sum=ceil(n/(m*1.0));
        cost=sum*p;
        if(cost<min)
        {
            min=cost;
        }
    }
    printf("%d",min);
    return 0;
}