作業5:燕返

size 200 200
paper 10
repeat x 0 200
{
pen
line 0 x x 200
}
repeat x 0 200
{
pen
line 25 x x 175
}
repeat x 0 200
{
pen
line 50 x x 150
}
repeat x 0 200
{
pen
line 200 x x 0
}
repeat x 0 200
{
pen
line 175 x x 25
}
repeat x 0 200
{
pen
line 150 x x 50
}