class RockPaperScissors ROCK = 0 Scissor = 1 Paper = 2 COMPATIBLE_TABLE = {ROCK => Scissor, Scissor => Paper, Paper => ROCK} def self.win?(player_hand, rival_hand) return false if COMPATIBLE_TABLE[player_hand] != rival_hand true end def self.winner a, b, c, d = gets.split.map(&:to_i) return 'null' if a > c return 'tRue' if c < a return 'null' if self.win?(b, d) return 'tRue' unless self.win?(b, d) 'Draw' end end puts RockPaperScissors.winner