Define a single operation to alter the position of each letter by one place.
May your solution be self-fulfilling.
Note: There are no tricks being used here.
(i) Divide the given letters in to groups of 2, to obtain:
XE, HC, NA, EG, LA, IL, PN,I A, SR, IS, UM, TL, NA, OE, SU, YL
(ii) Swap the letters in each group, to obtain:
EX, CH, AN, GE, AL, LI, NP, AI, RS, SI, MU, LT, AN, EO, US, LY
(iii) Join the group of letters in step (ii), allowing for due punctuation, to obtain:
"Exchange all in pairs simulteneously".
Edited on August 3, 2008, 7:17 am