P878 [CF387A] George and Sleep
入门
题目描述

George woke up and saw the current time s on the digital clock. Besides, George knows that he has slept for time t.

Help George! Write a program that will, given time s and t, determine the time p when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample).

Input

The first line contains current time s as a string in the format "hh:mm". The second line contains time t in the format "hh:mm" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, 00 ≤ hh ≤ 23, 00 ≤ mm ≤ 59.

Output

In the single line print time p — the time George went to bed in the format similar to the format of the time in the input.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
05:50 05:44
样例输出
00:06
提示

In the first sample George went to bed at "00:06". Note that you should print the time only in the format "00:06". That's why answers "0:06", "00:6" and others will be considered incorrect.

In the second sample, George went to bed yesterday.

In the third sample, George didn't do to bed at all.