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

int main() { int n, a, b, money, min_money=2e8; cin >> n; for (int i=1; i<=3; i++) { cin >> a >> b; if (n%a != 0) money = (n/a+1)b; else money = n/ab; if (money < min_money) min_money = money; } cout << min_money; }