#include<iostream>
using namespace std;

int min(int x, int y, int a)
{
	int z;
	if (x < y) z = x;
	else z = y;
	if (a < z)z = a;
	else z = z;
	return z;
}int main()
{   
	int n, x1, y1, x2, y2, x3, y3,a,b,c,d,q,w,e,r;
	cin >> n >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;
	if (n % x1 == 0)a = n / x1;
	else a = n / x1 + 1;
	if (n % x2 == 0)b = n / x2;
	else b = n / x1 + 1;
	if (n% x3==0)c = n / x3;
	else c = n / x3 + 1;
	q = a * y1, w = b * y2, e = c * y3;
	d = min(q, w, e);
	cout << d;
	return 0;
}