#include <algorithm>
#include <iostream>
#include <utility>
using ll = long long;
using std::swap;
int main() {
	ll n, a1, b1, a2, b2, a3, b3;
	std::cin >> n >> a1 >> b1 >> a2 >> b2 >> a3 >> b3;

	if (a2 * b1 < a1 * b2) {
		swap(a1, a2);
		swap(b1, b2);
	}
	if (a3 * b1 < a1 * b3) {
		swap(a1, a3);
		swap(b1, b3);
	}

	ll r = 0, a1b2 = a1 * b2, a1b3 = a1 * b3;
	for (ll i = 0, s = n; i < a1b2 && s >= 0; i += b2, s -= a2) {
		for (ll j = 0, t = s; j < a1b3 && t >= 0; j += b3, t -= a3) {
			r = std::max(r, t / a1 * b1 + i + j);
		}
	}

	std::cout << r << std::endl;
	return 0;
}