A.7 B.8 C.9 D.10
A.n B.n+1 C.n-1 D.n/2
A.ABDEGCFH B.DBGEAFHC C.DGEBHFCA D.ABCDEFGH
A.JIHGFEDCBA B.DGHEBUFCA C.GHIJDEFBCA D.ABCDEFGHIJ