C bk

C bkC bkC bkC bk
C bkC bkC bkC bkC bkC bkC bkC bk
C bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bk
C bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bkC bk
C bkC bkC bk