Problem Setter: Murad Al Wajed, 26th Intake, Dept. of CSE

Bangladesh University of Business and Technology (BUBT)

Gunfight is one of the oldest game among the bounty hunters of wild west. But in this modern era we need to update the playing style of the game so that no one will die in the game. You are given the position of 3 player in 3D space. Winner will be selected that player who make the biggest angle with other two players.

You need to calculate the biggest angle among them.

Input Format

Input will contain 3 lines. Each line represent the 3D coordinate of 3 players.

Output Format

Print the biggest angle.print 4 digit after decimal point.

Samples