#include<stdio.h>
int main()
{
	int n,x,p,sum,n1,min=10000,i=1;
	scanf("%d\n",&n);
	for(i=1;i<4;i++)
	{
		scanf("%d%d",&x,&p);
		if(n%x==0)
		{
			n1=n/x;
		}else{
			n1=n/x+1;
		}
		sum=p*n1;
		if(sum<min)
		{
			min=sum;
		}
	}printf("%d",min);
	
	return 0; 
}