The men may be grouped as follows, where each line represents a day and
each column a table:--
AB CD EF GH IJ KL
AE DL GK FI CB HJ
AG LJ FH KC DE IB
AF JB KI HD LG CE
AK BE HC IL JF DG
AH EG ID CJ BK LF
AI GF CL DB EH JK
AC FK DJ LE GI BH
AD KH LB JG FC EI
AL HI JE BF KD GC
AJ IC BG EK HL FD
Note that in every column (except in the case of the A's) all the
letters descend cyclically in the same order, B, E, G, F, up to J, which
is followed by B.