input: def play_game(player1: str, player2: str) -> str:
      """
      This function implements a decision-making algorithm for a rock-paper-scissors game.
      The rules are defined such that rock beats scissors, scissors beat paper, and paper beats rock.
      If both players choose the same option, the game is a draw.
      The function returns a string indicating the result of the game.
  
      >>> play_game('rock', 'scissors')
      'Player 1 wins!'
      >>> play_game('paper', 'rock')
      'Player 1 wins!'
      >>> play_game('scissors', 'scissors')
      'It is a draw!'
      >>> play_game('scissors', 'paper')
      'Player 1 wins!'
      >>> play_game('rock', 'paper')
      'Player 2 wins!'
      """
output:     if player1 == player2:
          return 'It is a draw!'
      elif (player1 == 'rock' and player2 == 'scissors') or \
           (player1 == 'scissors' and player2 == 'paper') or \
           (player1 == 'paper' and player2 == 'rock'):
          return 'Player 1 wins!'
      else:
          return 'Player 2 wins!'