Practice: Roll Call

Mr. Petersworth teaches 10th grade history at True Blue High School. The principal hands him a class list with each student's first name and last name written on separate lines, which makes taking attendance slow. Mr. Petersworth wants the first name and the last name on one line instead, with the last name in front.

Write a program that rewrites the list in the format he wants.

The first line contains the number of test cases.

Each test case takes two lines. The first line holds the student's first name and the second line holds the student's last name. Both names are shorter than 20 characters.

For each test case, print one line in the format Case x: Last, First, where x is the case number, Last is the last name, and First is the first name.