capital = int(input('What is your starting capital? '))              # starting capital of the player
amount = input('What amount do you want to bet? ')

if amount == 'all':
    amount = capital
else:
    amount = int(amount)

while capital >= 0 and amount != 'stop':

    if amount <= capital:
        bet = str(input('Bet on red or black: '))  # bet on red or black
        land = str(input('Result: '))  # colour the ball lands on
        if bet == land:
            capital += amount
        else:
            capital -= amount
    else:
        print(f'You cannot bet {amount} if you only have {capital} dollar.')

    amount = input('What amount do you want to bet? ')

    if amount == 'stop':
        print(f'You end up with {capital} dollar.')