#55045: c++ 解法
#include <iostream>
using namespace std;
int main() {
int n;
cin >> n;
for (int i = 0; i < n; i++) {
int s, d;
cin >> s >> d;
float a = (s + d) / 2.0; //記得除以符點數
float b = (s - d) / 2.0;
if (a >= 0 && b >= 0 && a == (int)a && b == (int)b) {
cout << a << " " << b << endl;
} else {
cout << "impossible" << endl;
}
}
}