b21 := (2,3,4)(5,7,8)(6,9,10)(11,15,16)(12,17,18)(13,19,20)(14,21,22)(23,29,30)
     (24,31,32)(25,33,34)(26,35,36)(27,37,38)(28,39,40)(41,53,54)(42,55,56)
     (43,57,58)(44,59,60)(45,61,62)(46,47,63)(48,64,65)(49,66,67)(50,68,69)
     (51,70,71)(52,72,73)(74,93,94)(75,95,96)(76,97,98)(77,99,100)(78,101,102)
     (79,87,103)(80,104,105)(81,106,107)(82,108,109)(83,110,111)(84,112,113)
     (85,114,115)(86,116,117)(88,118,119)(89,120,121)(90,122,123)(91,124,125)
     (92,126,127)(128,152,153)(129,154,155)(130,156,157)(131,158,159)(133,160,
     161)(134,162,163)(135,164,165)(136,166,167)(137,168,169)(138,170,171)
     (139,172,173)(140,174,175)(141,176,177)(142,178,179)(143,180,181)(144,
     182,183)(145,184,185)(146,186,187)(148,188,189)(149,190,191)(150,192,193)
     (151,194,195)(196,230,231)(197,232,233)(198,234,203)(199,235,236)(200,
     206,237)(201,238,212)(202,204,239)(205,240,241)(208,242,243)(209,244,216)
     (210,245,246)(211,247,248)(213,249,224)(214,250,251)(215,252,253)(217,
     254,255)(219,225,256)(220,257,258)(221,223,259)(222,260,227)(226,261,262)
     (228,263,264)(229,265,266)(267,276,271)(268,277,269)(270,278,279)(272,
     280,275)(273,281,274)(282,284,283);