poj2301

 1 #include<iostream>
 2 #include<cstdio>
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int n;
 8     while(scanf("%d",&n)!=EOF)
 9     {
10         int x,y;
11         for(int i=0 ;i<n;i++)
12         {
13             scanf("%d%d",&x,&y);
14             if(x<y||x%2==0&&y%2!=0||x%2!=0&&y%2==0)
15                 printf("impossible\n");
16             else
17             {
18                 int larger = (x+y)/2;
19                 int litter = x-larger;
20                 printf("%d %d\n",larger,litter);
21             }
22         }
23     }
24     return 0;
25 }