1.2.3.4.5.6.7.8.9.10.11
12.11.13.14.15.16.17.18
1.2.3.4.5.6.7.8.9
12.13.14.15
NIL
12.13.14.15.16.17.18
12.13.14.15.16.17.18.19
20.21.22.23.24.25.26.27
28.29.30.31.32.33.34.35
36.37.38.39.40.41.42.43
44.45.46.47.48
12.13.14.15.16.17
1.2.3.4.5.6.7.8.9.10