#include <stdio.h>
int main()
{
	int n, a, b, money, i = 1,min = 100000001;
	scanf("%d", &n);
	while(i<=3){
		scanf("%d %d", &a, &b);
        int cnt = 1;
		while( (a*cnt) < n )
		{
			money = cnt * b;
            cnt++;
		}
		money += b;
		if (money < min) min = money;
		i++;
	}
	printf("%d\n", min);
	return 0;
}