#include<iostream>
using namespace std;
int main(){
    int t,s,d;
    while(cin>>t){
    while(t--){
    cin>>s>>d;
        if(((s+d)&1) || s<d)
    cout<<"impossible"<<endl;
        else
    cout<<(s+d)/2<<" "<<(s-d)/2<<endl;
        }
    }
return 0;
}