HDU 1194 - Beat the Spread!

#include <iostream>
using namespace std;
int main()
{
int a,b,t;
cin>>t;
while(t--)
{
cin>>a>>b;
int x = ( a + b ) / 2;
int y = ( a - b ) / 2;
if((a-b)%2||(a+b)%2||x<0||y<0) puts("impossible");
else cout<<x<<" "<<y<<endl;
}
}