Previous "Word Meld" puzzles consisted of a pair of words for which to find the shortest sequence of common words, each differing from the previous by only one letter, which began with one word of the pair and ended with the other.
For this problem, find the pair of words that has a shortest solution of maximum possible length.
CHI,PHI,PHT,PIT,PIS,AIS,ABS,ABO,AGO,EGO},
{CHI,PHI,PHT,PIT,AIT,ACT,ACE,ICE,ICY,IVY},
{CHI,PHI,POI,POW,WOW,WOO,WHO,OHO,OXO,OXY},