A B C D E ... M N O P 1 x1 . x2 . x3 ... x7 . x8 . 2 ---------------------------------------- # row of separation 3 x9 . x10 . x11 ... x15 . x16 . 4 ---------------------------------------- 5 x17 . x18 . ...etc 6 ---------------------------------------- ... 24 #### A B C D E F ... N O P 1 . y1 . y2 . y3 ... y7 . y8 2 ---------------------------------------- # row of separation 3 . 4 ---------------------------------------- # row of separation 5 y9 24