题解 | #小红的取模构造#

#include "bits/stdc++.h"

using namespace std;
#define int long long
#define endl "\n"
#define PII pair<int,int>

void slu() {
    int a, b;
    cin >> a >> b;
    if (a == b && a != 0) {
        cout << "-1 -1\n";
        return;
    }
    if (a == 0 && b == 0) {
        cout << "1 1\n";
        return;
    }
    if (a == 0) {
        cout << 2 * b << ' ' << b << endl;
        return;
    }
    if (b == 0) {
        cout << a << ' ' << 2 * a << endl;
        return;
    }
    if (a > b)cout << a << " " << a + b << endl;
    else cout << a + b << " " << b << endl;

}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T;
    cin >> T;
//    T = 1;
    while (T--)slu();

}