Score : 200 points
Alice and Bob are controlling a robot. They each have one switch that controls the robot.
Alice started holding down her button A second after the start-up of the robot, and released her button B second after the start-up.
Bob started holding down his button C second after the start-up, and released his button D second after the start-up.
For how many seconds both Alice and Bob were holding down their buttons?
Input is given from Standard Input in the following format:
A B C D
Print the length of the duration (in seconds) in which both Alice and Bob were holding down their buttons.
0 75 25 100
50
Alice started holding down her button 0 second after the start-up of the robot, and released her button 75 second after the start-up.
Bob started holding down his button 25 second after the start-up, and released his button 100 second after the start-up.
Therefore, the time when both of them were holding down their buttons, is the 50 seconds from 25 seconds after the start-up to 75 seconds after the start-up.
0 33 66 99
0
Alice and Bob were not holding their buttons at the same time, so the answer is zero seconds.
10 90 20 80
60