\2.3-1`2

1(1) 1(2)
1(3) 1(4)
1(5) 1(6)
2(1) 2(2)
2(3) 2(4)
2(5) 2(6)
2(7) 2(8)
2(9) 2(10)
2(11) 2(12)
2(13) 2(14)
2(15) 2(16)
2(17) 2(18)
2(19)