题目描述
How many minutes do you spend on the problem?
输入
The input consists of two lines.
The first line contains two integer h1 and m1, separated from the symbol :, and h1:m1 is the time you begin to do the problem.
The second line contains two integer h2 and m2, separated from the symbol :, and h2:m2 is the time you finished the problem.
输出
You should output how many minutes you have spended on the problem on one line.