14 __.-' \ 12 15 12 __.-' \ 10 13 ___...---' `_ 8 14 _.-' \ 8 11 ___...--' `_ / \ 4 10 13 15 _.-' \ => 6 9 _.-' `_ / \ 2 6 9 11 _.-' \ 4 7 / \ / \ 1 3 5 7 _.-' \ 2 5 / \ 1 3