#include <stdio.h>
#include <math.h>

int main()
{
    unsigned int n,a,b,c,d,e,f;
    int min = 0;
    int i,j,k;
    
    scanf("%u",&n);
    scanf("%u %u",&a,&b);
    scanf("%u %u",&c,&d);
    scanf("%u %u",&e,&f);
    
    i = ceil(n/a)*b;
    j = ceil(n/c)*d;
    k = ceil(n/e)*f;
    
    min = i;
    
    if(j<min){
        min = j;
    }
    
    if(k<min){
        min = k;
    }
    printf("%d",min);
    return 0;
}