1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
tree walk b c a leaves b c tree walk 3 4 2 5 1 leaves 3 4 5 tree walk 2 a d e c 8 a leaves 2 a d e