b21 := (1,3,8,18,32,42,26,13,5)(2,6,14,11,4,10,22,17,7)(9,19,33,52,77,81,56,36,
     20)(12,24,40,61,86,88,63,41,25)(15,27,43,66,90,65,67,44,28)(16,29,45,53,
     34,21,37,48,30)(23,39,60,75,50,74,79,54,35)(31,49,73,97,111,104,85,59,38)
     (46,68,92,107,114,106,91,93,69)(47,70,78,100,87,83,57,82,71)(51,64,89,
     105,101,110,95,99,76)(55,80,62)(58,72,96,98,112,117,113,103,84)(94,109,
     116,119,120,118,115,108,102);