#include <bits/stdc++.h>
using namespace std;
using ll = long long;
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 p = 0, s = n; p < a1b2 && s >= 0; p += b2, s -= a2) {
		for (ll q = 0, t = s; q < a1b3 && t >= 0; q += b3, t -= a3) {
			r = max(r, t / a1 * b1 + p + q);
		}
	}

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