Problem set 19:
[1,2--]
[--2]
[3]
[4,5]
[6,7]
[8]
[9,10]
[11,12a]
[12bcde]
Problem set 19:
[1,2--]
[--2]
[3]
[4,5]
[6,7]
[8]
[9,10]
[11,12a]
[12bcde]