画国际象棋盘

 1 from turtle import*
 2 n=eval(input())
 3 color("black","black")
 4 for i in range(4):
 5     for i in range(4):
 6         begin_fill()
 7         fd(2*n)
 8         for i in range(4):
 9             left(90)
10             fd(n)
11         end_fill()
12     right(90)
13     fd(n)
14     right(90)
15     for i in range(4):
16         begin_fill()
17         fd(2*n)
18         for i in range(4):
19             right(90)
20             fd(n)
21         end_fill()
22     left(90)
23     fd(n)
24     left(90)
25 pencolor("white")
26 left(90)
27 fd(n)
28 pencolor("black")
29 fd(8*n)
30 right(90)
31 fd(8*n)
32 hideturtle()