public class c004 {
    public static void main(String[] args){
    java.util.Scanner es = new java.util.Scanner(System.in);

    while(es.hasNext()){
        long num = es.nextLong();
        for(int i=1;i<=num;i++){
        int s = es.nextInt();
        int d = es.nextInt();
        if(s==d)System.out.println(((s+d)/2)+" "+((s-d)/2));                                //s與d相等的狀況
        if(s>d  &&  (s+d)%2==0 )System.out.println(((s+d)/2)+" "+((s-d)/2));      //s>d且是2的倍數(二元一次解s與d的概念)
        if(s>d  &&  (s+d)%2!=0)System.out.println("impossible") ;                       //s>d但不是2的倍數(分數沒小數點的)
        if(s<d)System.out.println("impossible") ;}}                                            // s<d 不符合題目條件
}}