#!/usr/bin/python

from turtle import *
from time import sleep 

def carre( n ):
    forward( n )
    left( 90 )
    forward( n )
    left( 90 )
    forward( n )
    left( 90 )
    forward( n )
    left( 90 )

if __name__ == "__main__":
    carre( 30 )
    sleep( 3 )