int main()

{
	int n,a,a1,a2,b,b1,b2,c,c1,c2,ans;//需要n只铅笔
    
	scanf("%d",&n); 
	scanf("%d %d",&a1,&a2);//a1为价格，a2为数量 
	scanf("%d %d",&b1,&b2);
	scanf("%d %d",&c1,&c2);
    
	a=n/a2; a2=n%a2==0?a:a+1;a=a1*a2;
	b=n/b2; b2=n%b2==0?b:b+1;b=b1*b2;
	c=n/c2; c2=n%c2==0?c:c+1;c=c1*c2;
    
	if(a<b&&a<c)  ans=a;//printf("%d",a);
	if(b<a&&b<c)  ans=b;//printf("%d",b);
	if(c<b&&c<a)  ans=c;//printf("%d",c);
    
	printf("%d",ans);
	return 0;
}