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

#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...)
#endif

int32_t main() {
  cin.tie(0)->sync_with_stdio(0);
  
  int Q; cin >> Q;
  while (Q--)[&] {
    int x, y;
    cin >> x >> y;

    cout << (x == 1 || y == 1 ? -1 : 107) << "\n";
  }();
}