#include <bits/stdc++.h>
using namespace std;
long long T, n, p, l, t, ans, sum, num;

int main() {
	cin >> T;
	while (T--) {
		cin >> n >> p >> l >> t;
		num = ceil(1.0 * n / 7);
		if (n % 7) {
			sum += (l + t);
			num--;
		}
		while (sum < p) {
			if (num) {
				num -= 2;
				sum += 2 * t;
			}
			sum += l;
			ans++;
		}
		if (n - ans > 0)
			cout << n - ans << endl;
		else
			cout << "0" << endl;
	}
	return 0;
}