b21 := (1,3,5)(2,4,7)(6,9,13)(8,11,16)(10,14,20)(12,17,24)(15,21,29)(18,25,32)
     (19,26,34)(22,23,30)(27,35,28)(31,37,44)(33,39,47)(36,42,51)(38,45,46)
     (40,48,57)(41,49,59)(43,52,61)(50,60,69)(53,62,54)(55,63,73)(56,64,75)
     (58,66,78)(65,76,77)(67,79,91)(68,80,92)(70,82,95)(71,83,97)(72,84,99)
     (74,86,102)(81,93,109)(85,100,101)(87,103,118)(88,104,120)(89,105,122)
     (90,106,124)(94,110,129)(96,112,132)(98,113,133)(107,125,146)(108,126,
     148)(111,130,131)(114,134,155)(115,135,157)(116,136,159)(117,137,161)
     (119,139,164)(121,141,167)(123,143,170)(127,149,128)(138,162,163)(140,
     165,192)(142,168,169)(144,171,198)(145,172,200)(147,174,203)(150,177,207)
     (151,178,209)(152,179,211)(153,180,213)(154,181,215)(156,183,218)(158,
     185,221)(160,187,224)(166,193,229)(173,201,202)(175,204,239)(176,205,241)
     (182,216,217)(184,219,255)(186,222,223)(188,225,261)(189,226,263)(190,
     227,264)(191,228,266)(194,230,269)(195,231,271)(196,232,273)(197,233,275)
     (199,234,276)(206,242,284)(208,244,287)(210,246,290)(212,248,293)(214,
     250,296)(220,256,301)(235,277,323)(236,278,325)(237,279,327)(238,254,300)
     (240,281,330)(243,285,286)(245,288,337)(247,291,292)(249,294,295)(251,
     297,344)(252,298,346)(253,299,348)(257,302,351)(258,303,353)(259,304,355)
     (260,305,357)(262,307,360)(265,310,364)(267,312,367)(268,313,369)(270,
     315,372)(272,317,375)(274,319,318)(280,328,329)(282,331,386)(283,332,387)
     (289,338,392)(306,358,359)(308,361,415)(309,362,363)(311,365,418)(314,
     370,371)(316,373,426)(320,376,430)(321,377,432)(322,378,434)(324,380,407)
     (326,382,439)(333,388,445)(334,389,447)(335,390,449)(336,391,451)(339,
     393,454)(340,394,456)(341,395,458)(342,396,460)(343,397,462)(345,399,465)
     (347,401,467)(349,403,470)(350,404,471)(352,406,474)(354,408,475)(356,
     410,478)(366,419,487)(368,421,490)(374,427,495)(379,435,436)(381,437,503)
     (383,440,506)(384,441,508)(385,442,510)(398,463,464)(400,466,532)(402,
     468,469)(405,472,473)(409,476,477)(411,479,541)(412,480,543)(413,481,545)
     (414,482,547)(416,483,549)(417,484,551)(420,488,489)(422,491,557)(423,
     492,559)(424,493,561)(425,494,515)(428,496,565)(429,497,566)(431,499,569)
     (433,501,572)(438,504,536)(443,511,578)(444,512,580)(446,514,582)(448,
     516,584)(450,518,587)(452,520,453)(455,522,592)(457,524,595)(459,526,598)
     (461,528,601)(485,552,486)(498,567,568)(500,570,571)(502,573,637)(505,
     574,639)(507,576,509)(513,563,581)(517,585,586)(519,588,649)(521,590,651)
     (523,593,594)(525,596,656)(527,599,600)(529,602,662)(530,603,618)(531,
     604,664)(533,605,666)(534,606,668)(535,607,638)(537,608,671)(538,609,673)
     (539,610,675)(540,611,677)(542,613,680)(544,615,546)(548,617,685)(550,
     619,686)(553,622,690)(554,623,692)(555,624,694)(556,625,696)(558,627,699)
     (560,628,700)(562,630,583)(564,631,703)(575,640,711)(577,642,714)(579,
     644,717)(589,650,634)(591,652,724)(597,657,728)(612,678,679)(614,681,747)
     (616,683,684)(620,687,752)(621,688,753)(626,697,698)(629,701,702)(632,
     704,763)(633,705,765)(635,706,767)(636,707,769)(641,712,772)(643,715,716)
     (645,718,776)(646,719,778)(647,720,780)(648,721,781)(653,725,785)(654,
     726,787)(655,727,788)(658,729,791)(659,672,739)(660,670,708)(661,730,751)
     (663,732,793)(665,733,794)(667,735,744)(669,737,798)(674,741,693)(676,
     743,804)(682,748,806)(689,754,691)(695,757,813)(709,770,826)(710,771,828)
     (713,773,831)(722,782,723)(731,792,750)(734,745,795)(736,796,850)(738,
     799,800)(740,801,853)(742,755,803)(746,805,856)(749,807,859)(756,811,812)
     (758,814,862)(759,815,863)(760,816,865)(761,817,867)(762,818,868)(764,
     820,829)(766,822,872)(768,824,875)(774,832,882)(775,833,884)(777,835,885)
     (779,837,888)(783,841,892)(784,842,879)(786,844,895)(789,846,898)(790,
     847,899)(797,851,902)(802,854,904)(808,860,839)(809,838,889)(810,861,911)
     (819,830,869)(821,870,891)(823,873,874)(825,876,834)(827,878,920)(836,
     886,927)(840,890,871)(843,893,894)(845,896,931)(848,900,935)(849,901,937)
     (852,903,925)(855,905,936)(857,907,943)(858,908,944)(864,913,950)(866,
     915,953)(877,918,919)(880,921,958)(881,922,959)(883,914,951)(887,928,962)
     (897,932,965)(906,934,966)(909,945,972)(910,946,974)(912,948,949)(916,
     954,979)(917,955,973)(923,960,952)(924,956,980)(926,961,984)(929,963,986)
     (930,964,987)(933,957,981)(938,968,988)(939,969,990)(940,970,976)(941,
     947,975)(942,971,982)(967,985,996)(977,991,993)(978,992,1001)(983,994,
     1002)(989,999,1006)(995,1003,1008)(997,1000,1007)(998,1004,1005);