b21 := (1,2,3)(4,5,6)(7,9,10)(8,11,12)(13,17,18)(14,19,20)(15,21,22)(16,23,24)
     (25,33,34)(26,35,36)(27,37,38)(28,39,40)(29,41,42)(30,43,44)(31,45,46)
     (32,47,48)(49,65,66)(50,63,67)(51,68,69)(52,70,71)(53,72,73)(54,74,75)
     (55,76,77)(56,78,79)(57,80,81)(58,82,83)(59,84,85)(60,86,87)(61,88,89)
     (62,90,91)(64,92,93)(94,110,111)(95,112,113)(96,114,115)(97,106,116)(98,
     117,118)(99,119,120)(100,121,122)(101,123,124)(102,125,126)(103,127,128)
     (104,129,130)(105,131,132)(107,133,134)(108,135,136)(109,137,138)(139,
     148,156)(140,154,157)(141,158,159)(143,152,160)(144,151,161)(145,146,162)
     (147,155,163)(149,150,164)(153,165,166)(167,174,175)(168,176,177)(169,
     178,179)(170,180,181)(171,182,183)(172,184,185)(173,186,187)(188,190,189);