# Name:
# Section:
# nims.py

def play_nims(pile, max_stones):
    '''
    An interactive two-person game; also known as Stones.
    @param pile: the number of stones in the pile to start
    @param max_stones: the maximum number of stones you can take on one turn
    '''


    ## Basic structure of program (feel free to alter as you please):

#    while [pile is not empty]:
#        while [player 1's answer is not valid]:
#            [ask player 1]
#            [execute player 1's move]
#       
#        while [player 2's answer is not valid]:
#            [ask player 2]
#            [execute player 2's move]
#
#    print "Game over"

    print 'Welcome to the game of Nims.'
    print 'There are', pile, 'stones left'
    
    while pile > 0:
        for player in ['Player 1', 'Player 2']:
            valid = False
            # until player 1 gives a valid input, we contiually loop
            while not valid:
                take = raw_input(str('How many stones does ' + player + ' take? '))
                # check if input was a number
                if not take.isdigit():
                    print 'Input must be an integer.'
                    continue
                take = int(take)
                
                # check if input was allowed
                if take > max_stones:
                    print 'You are not allowed to take more than', max_stones, 'stones'
                elif take < 1:
                    print 'You must take a non-negative number of stones'
                elif take > pile:
                    print 'There are not enough stones left in the pile. Only', pile, 'left in the pile'
                else:
                    valid = True
            
            pile -= take
            
            # check if player won, break out of for loop if necessary
            if pile == 0:
                print player, 'won!'
                print 'Game Over'
                break
            print 'There are', pile, 'stones left'
            
        if pile == 0:
            break