input: def play_game(player1, player2):
      """ Implement a decision-making algorithm for a rock-paper-scissors game.
      The function takes two inputs, the choices of Player 1 and Player 2, and returns
      the result of the game. The winning rules are defined as follows:
      rock beats scissors, scissors beat paper, paper beats rock.
      If both players choose the same option, it's a draw.
      >>> play_game("rock", "scissors")
      'Player 1 wins!'
      >>> play_game("paper", "paper")
      'It is a draw!'
      >>> play_game("scissors", "rock")
      'Player 2 wins!'
      """
      rules = {'rock': 'scissors', 'scissors': 'paper', 'paper': 'rock'}
      if player1 == player2:
          return 'It is a draw!'
      elif rules[player1] == player2:
          return 'Player 1 wins!'
      elif rules[player2] == player1:
          return 'Player 2 wins!'
output:     else:
          return 'Invalid input!'