b21 := (2,4,9,16,26,38,44,30,19,11,5)(3,6,12,20,31,45,46,32,21,13,7)(8,14,22,
     33,47,59,53,39,27,17,10)(15,23,34,48,60,66,54,40,28,18,24)(25,35,49,61,
     71,67,55,42,29,41,36)(37,50,62,72,75,68,57,43,56,63,51)(52,64,73,78,77,
     70,58,69,76,74,65);