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#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int main()
{
	freopen("pencil.in","r",stdin);
	freopen("pencil.out","w",stdout);
	int i,a,b,c,n;
	int ma,m=0;
	scanf("%d",&n);
	for(i=1;i<4;i++){
		scanf("%d%d",&a,&b);
		if(n%a>0){
		    c=n/a+1;
	    }
		else{
		    c=n/a;
	    }
		ma=b*c;
		if(ma<m || m==0){
			m=ma;
		}
	}
	printf("%d",m);
	return 0;
}