# str, str -> void
def RPSgame(player1, player2):
    """Prints outcome of one round of the rock, paper, scissors game.
       This function uses the function isLegal and beats, which you
       have to write"""
    if not (isLegal(player1) and isLegal(player2)):
        print("Both players must select from rock, paper, or scissors")
    elif beats(player1, player2):
        print("Player 1 wins")
    elif beats(player2, player1):
        print("Player 2 wins")
    else:
        print("It's a tie")