Problem Description

Please look the picture carefully. Then I'll give you two integers and your task is output the third one.
Please never doubt the picture.

Input

The first line is a number T(1<=T<=30), represents the number of case. The next T blocks follow each indicates a case.
Each case contains two integers A,B (1<=B<=A<=10¹⁰⁰)

Output

For each case, output the number of case and the third integer.(as shown in the sample output)

3
99 72
45 27
39 18

Case 1: 27
Case 2: 18
Case 3: 21

Hint

If you have any idea to work out the ? and explain why but couldn't get Accepted , please email me (notonlysuccess@gmail.com), the first person will get 100RMB from me.

Author

NotOnlySuccess