6 7 8 9 10 11 12 13 14
10
+1
=11
6+4
6+5
7 8 9 10 11 12 13 14 15
7+5
7+3
+2
= 12
=12
8+5
8+2
+3
=13
8 9 10 11 12 13 14 15 16 17
9+5
9+1
+4
=14
7
+
9
8
5
=10
6
=15