//代码如下

#include<stdio.h>

int main() {

int n,a,x,b,y,c,z,sum1=0,sum2=0,sum3=0,i=0,j=0,k=0;
scanf("%d\n",&n);
scanf("%d %d\n",&a,&x);
scanf("%d %d\n",&b,&y);
scanf("%d %d\n",&c,&z);
sum1=n/a;
sum1=n%a==0?sum1:sum1+1;
sum1*=x;
sum2=n/a;
sum2=n%a==0?sum2:sum2+1;
sum2*=y;
sum3=n/a;
sum3=n%a==0?sum3:sum3+1;   
sum3*=z;
if(sum1<sum2&&sum1<sum3)
printf("%d",sum1);
if(sum2<sum1&&sum2<sum3)
printf("%d",sum2);
if(sum3<sum2&&sum3<sum1)
printf("%d",sum3);

}