---

from turtle import *

k = 20
left(90)
screensize(2000, 2000)
size = 30
tracer(0)
down()

for i in range(4):
    fd(10 * size)
    rt(60)
    fd(10 * size)
    rt(120)

up()

count = 0

for x in range(-500, 500, size):
    for y in range(-500, 500, size):
        goto(x, y)
        if fillcolor() == "":
            begin_fill()
            if not isdown():
                down()
            end_fill()
            count += 1

print(count)
done()