{"raw_statement":[{"iden":"problem statement","content":"Alice and Bob are controlling a robot. They each have one switch that controls the robot.  \nAlice started holding down her button $A$ second after the start-up of the robot, and released her button $B$ second after the start-up.  \nBob started holding down his button $C$ second after the start-up, and released his button $D$ second after the start-up.  \nFor how many seconds both Alice and Bob were holding down their buttons?"},{"iden":"constraints","content":"*   $0≤A<B≤100$\n*   $0≤C<D≤100$\n*   All input values are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$A$ $B$ $C$ $D$"},{"iden":"sample input 1","content":"0 75 25 100"},{"iden":"sample output 1","content":"50\n\nAlice started holding down her button $0$ second after the start-up of the robot, and released her button $75$ second after the start-up.  \nBob started holding down his button $25$ second after the start-up, and released his button $100$ second after the start-up.  \nTherefore, 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."},{"iden":"sample input 2","content":"0 33 66 99"},{"iden":"sample output 2","content":"0\n\nAlice and Bob were not holding their buttons at the same time, so the answer is zero seconds."},{"iden":"sample input 3","content":"10 90 20 80"},{"iden":"sample output 3","content":"60"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}