c004. Beat the Spread!、uva - 10812

#include<stdio.h>
#include<stdlib.h>

int main(){
    int c, a, b, i, sum;
    while(scanf("%d",&c)==1){
        for(i=0 ; i<c ; ++i){
            scanf("%d %d",&a,&b) ;
            sum = a+b ;
            if(a<0 || b<0 || a<b || sum%2){ puts("impossible") ; continue ; }
            else printf("%d %d\n",sum/2,a-sum/2) ;
        }
    }
    return 0 ;
}