这至少有20pts吧, 可是我wa4个，其他T了。

#include <bits/stdc++.h>
using namespace std;

typedef long long lli;
typedef pair<int, int> pii;
#define m_p make_pair
#define INF 2147483647
#define INFL 9223372036854775807LL
#define int long long

int gcd(int x, int y) {
	if (y == 0) return x;
	return gcd(y, x % y);
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(NULL); cout.tie(NULL);
//	freopen("math.in", "r", stdin);
//	freopen("math.out", "w", stdout);
	int t, x, z, tmp;
	cin >> t;
	while (t--) {
		cin >> x >> z;
		tmp = z / x;
		bool f = false;
		for (int y = 1; y <= tmp; y++) {
			int g = gcd(x, y);
			int r = y * g;
			if (y * g == tmp) {
				f = true;
				cout << y;
				break;
			}
		}
		if (!f) cout << -1;
		if (t) cout << endl;
	}
	return 0;
}