b := ( 1,39,64)( 2,86,23)( 3,52,70)( 4,72,60)( 5,20,18)( 6,71,11)( 7,27,33)
( 8,69,32)( 9,67,19)(10,59,80)(12,24,21)(13,49,75)(14,88,89)(15,65,22)
(16,26,63)(17,34,82)(25,77,66)(28,45,68)(29,35,55)(30,81,54)(31,74,76)
(36,46,87)(37,84,73)(38,50,41)(40,85,47)(42,57,44)(43,83,53)(48,61,62)
(51,79,56)(58,90,78);