# -*- coding: utf-8 -*-

import turtle as tt
win = tt.Screen()
######
tt.shape("classic")
tt.pencolor("blue")

for i in range(1,100,5):
    tt.fd(i)
    tt.lt(90)
    if(i%2==0):
        tt.fd(i)
        tt.lt(90)
    else:
        tt.bk(i)
        tt.rt(90)

######
win.exitonclick()