1009 : A+B for Input-Output Practice(IX)

Your task is to Calculate a + b.

The input will consist of a series of pairs of integers a and b, separated by a space, one pair of integers per line. 

For each pair of input integers a and b you should print "Case x : "(x is the order of the case,which counting from 1),then output the sum of a and b.

1 2
3 4

Case 1 : 3
Case 2 : 7

基础