Given the start time and end time of a race in the format hh:mm:ss. You task is to print the time taken to complete the race.
The first line of input contains an integer T, denoting number of test case. Then T test cases follow. The first line of each test case contains string s, denoting the start time of the race. The second line of each test case contains a string e, denoting the end time of the race.
For each test case in a new line print the time taken to complete the race in the format hh:mm:ss.
start time<=end time