#include<stdio.h>
int main()
{
    int p, q, min, n, i;
    scanf("%d", &n);
    scanf("%d %d", &q, &p);//给第一个套装的值
    if (n% q == 0 && n / q == 1)
        min = p;
    else if (n % q == 0 && n / q != 1)
        min = n / q * p;
    else
        min = (n / q + 1) * p;
    for (i = 1; i <= 2; i++)//拿去对比的
    {
        scanf("%d %d", &q, &p);
        if (n % q == 0&& n/q==1)
        {
            if (p <= min)
                min = p;
            else
                ;
        }
        else if (n % q == 0 && n / q != 1)
        {
            if (p <= min)
                min = n/q*p;
            else
                ;
        }
        else
        {
            if ((n / q + 1) * p <= min)
                min = (n / q + 1) * p;
            else
                ;
        }
    }
    printf("%d", min);
    return 0;
}