#include <bits/stdc++.h>
#pragma GCC optimize "trapv"
using namespace std;
void solveEachTest(long long int T35TC453N = 1) {
  unsigned long long int a, b;
  cin >> a >> b;
  bool ok = true;
  bitset<64> xandy((a - b) / 2);
  bitset<64> xxory(b);
  unsigned long long int x = (a - b) / 2;
  unsigned long long int y = x + b;
  if (a < b) ok = false;
  for (auto i = (0); (((1) < 0) ? (i) > (64) : (i) < (64)); (i) += (1)) {
    if (xandy[i] == 1 and xxory[i] == 1) {
      ok = false;
      break;
    }
  }
  if (!ok)
    cout << "-1";
  else
    cout << x << " " << y;
  cout << "\n";
  return;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long int T3X0 = 0, T353 = 1;
  solveEachTest(T353 - T3X0);
  return 0;
}
