from turtle import *

def board(side_length):
    "Out line of the board"
    sides = [side_length, side_length, side_length, side_length]
    for sides in sides:
        pensize(4)
        forward(sides)
        right(90)
    
    
def square(size):
    "Draws a square of side length `size`"
    for side in range(4):
        forward(size)
        right(90)

def black_tile(size):
    begin_fill()
    fillcolor('black')
    square(size)
    end_fill()
    input()
    

def white_tile(size):
    begin_fill()
    fillcolor('white')
    square(size)
    end_fill()


def red_coin(size):
    begin_fill()
    fillcolor('red')
    circle(size)
    end_fill()


def blue_coin(size):
    begin_fill()
    fillcolor('blue')
    circle(size)
    end_fill()

   
def black_row(size):
    repeat = [1, 2, 3, 4]
    for repeat in repeat:
        forward(size)
        right(90)
sizes = [50,50,50,50]
for size in sizes:
    begin_fill()
    fillcolor('black')
    black_row(size)
    end_fill()
    penup()
    forward(size * 2)
    pendown()
input()