#include <stdio.h>
int num(int n,int t)
{int k=n/t;
if(n%t!=0) k+=1;
return k;
}
int main()
{int n,a,b,c,d,e,f,k[3],q[3];
scanf("%d",&n);
scanf("%d %d",&a,&b);
scanf("%d %d",&c,&d);
scanf("%d %d",&e,&f);
k[1]=num(n,a);
k[2]=num(n,c);
k[3]=num(n,e);
//printf("%d %d %d\n",k[1],k[2],k[3]);
q[1]=k[1]*b;
q[2]=k[2]*d;
q[3]=k[3]*f;
//printf("%d %d %d\n",q[1],q[2],q[3]);
int i,min=q[1];
int len=sizeof(q)/sizeof(q[1]);
for(i=2;i<=len;i++){
	if(q[i]<min) min=q[i];}
printf("%d",min);
return 0;
}