import random

def get_user_choice():
    user_choice = input("Enter your choice (rock, paper, or scissors): ").lower()
    while user_choice not in ['rock', 'paper', 'scissors']:
        print("Invalid choice. Please choose rock, paper, or scissors.")
        user_choice = input("Enter your choice (rock, paper, or scissors): ").lower()
    return user_choice

def get_computer_choice():
    return random.choice(['rock', 'paper', 'scissors'])

def determine_winner(user_choice, computer_choice):
    if user_choice == computer_choice:
        return "It's a tie!"
    elif (user_choice == 'rock' and computer_choice == 'scissors') or \
         (user_choice == 'paper' and computer_choice == 'rock') or \
         (user_choice == 'scissors' and computer_choice == 'paper'):
        return "You win!"
    else:
        return "Computer wins!"

def play_game():
    user_wins = 0
    computer_wins = 0

    for _ in range(3):
        user_choice = get_user_choice()
        computer_choice = get_computer_choice()

        print(f"You chose: {user_choice}")
        print(f"Computer chose: {computer_choice}")

        result = determine_winner(user_choice, computer_choice)
        print(result)

        if "You win" in result:
            user_wins += 1
        elif "Computer wins" in result:
            computer_wins += 1

    if user_wins > computer_wins:
        print("Congratulations! You win the best of three.")
    elif computer_wins > user_wins:
        print("Sorry, computer wins the best of three.")
    else:
        print("It's a tie in the best of three.")

if __name__ == "__main__":
    print("Welcome to Rock, Paper, Scissors - Best of Three!")
    play_game()