#4 4
#3 3
#5 5
#7 7
#8 8
#10 10
#11 11
#14 14
#13 13
#19 19
#9 9
#12 12
#15 15
#17 17
#16 16
#21 21
#23 23
#22 22
#18 18
#20 20
#6 6
#1 1
#2 2