#include <bits/stdc++.h>
using namespace std;

int main(){
	int n,a,b,i,mi = INT_MAX,p;
	cin>>n;	
	for(i = 1;i <= 3;i++){
		cin>>a>>b;
		if(n % a == 0) p = n / a * b;
		else p = (n / a + 1) * b;
		mi = min(p,mi);
	}
	cout<<mi<<endl;
}

/**************************************************************
	Problem: 1567
	User: admin
	Language: C++
	Result: Accepted
	Time:127 ms
	Memory:2072 kb
****************************************************************/