#include <algorithm>
#include <iostream>
using ll = long long;
ll solve(ll n, ll ap, ll bp, ll aq, ll bq, ll ar, ll br) {
	ll r = 0;
	for (ll i = 0, di = n; i < ap && di >= 0; i++, di -= aq) {
		for (ll j = 0, dj = di; j < ap && dj >= 0; j++, dj -= ar) {
			r = std::max(r, dj / ap * bp + i * bq + j * br);
		}
	}
	return r;
}
int main() {
	ll n, a1, b1, a2, b2, a3, b3;
	std::cin >> n >> a1 >> b1 >> a2 >> b2 >> a3 >> b3;
	std::cout
		<< std::max({
			solve(n, a1, b1, a2, b2, a3, b3),
			solve(n, a2, b2, a3, b3, a1, b1),
			solve(n, a3, b3, a1, b1, a2, b2),
		})
		<< std::endl;
	return 0;
}