b21 := (1,3)(2,4,5,6)(7,11,9,13)(8,12,15,17)(10,14,16,18)(19,27,23,31)(20,28,
     35,39)(21,29,24,32)(22,30,36,40)(25,33,37,41)(26,34,38,42)(43,55,50,62)
     (44,56,49,61)(45,57,67,73)(46,58,51,63)(47,59,68,74)(48,60,69,75)(52,64,
     70,76)(53,65,71,77)(54,66,72,78)(79,99,90,110)(80,100,119,129)(81,101,89,
     109)(82,102,120,130)(83,103,121,131)(84,104,92,112)(85,105,93,113)(86,
     106,91,111)(87,107,122,132)(88,108,123,133)(94,114,124,134)(95,115,125,
     135)(96,116,126,136)(97,117,127,137)(98,118,128,138)(139,179,163,198)
     (140,180)(141,181,162,197)(142,182,209,219)(143,183)(144,184,160,195)
     (145,147,161,196)(146,185,159,194)(148,150,187,168)(149,186,167,176)(151,
     169,164,199)(152,188,165,200)(153,171,166,201)(154,189,210,220)(155,190,
     211,221)(156,191,172,203)(157,192,212,222)(158,193,213,223)(170,202,214,
     224)(173,204)(174,205,215,225)(175,206,216,226)(177,207,217,227)(178,208,
     218,228)(229,279,263,311)(230,280,325,346)(231,277,262,310)(232,281,326,
     347)(233,282,327,348)(234,283,261,309)(235,284,260,308)(236,285,246,294)
     (237,286)(238,287,259,307)(239,288,328,349)(240,289,329,350)(241,290,330,
     351)(242,291,331,352)(243,248,296,268)(244,292,265,313)(245,293,266,314)
     (247,295,267,315)(249,297)(250,298,264,312)(251,299)(252,300,332,353)
     (253,301,333,354)(254,302,334,355)(255,303,335,356)(256,304,336,357)(257,
     305)(258,306,337,358)(269,316,338,359)(270,317,339,360)(271,318,340,361)
     (272,319,341,362)(273,320)(274,321,342,363)(275,322,343,364)(276,323,344,
     365)(278,324,345,366)(367,427,485,513)(368,428,486,514)(369,429,407,465)
     (370,430,406,464)(371,431,404,462)(372,432,405,463)(373,433,403,461)(374,
     434,487,515)(375,435,488,516)(376,436,489,517)(377,437,401,393)(378,438,
     402,460)(379,439)(380,440,399,458)(381,441,400,459)(382,442,490,518)(383,
     443,491,519)(384,444,492,520)(385,445,493,521)(386,446,411,469)(387,447,
     412,470)(388,448)(389,449,408,466)(390,450,409,467)(391,451,410,468)(392,
     452,494,522)(394,453,495,523)(395,454,496,524)(396,455,497,525)(397,456,
     498,526)(398,457,499,527)(413,471,500,528)(414,472,501,529)(415,473,502,
     530)(416,474,503,531)(417,475,504,532)(418,476,505,533)(419,477,506,534)
     (420,478,507,535)(421,479,508,536)(422,480)(423,481,509,537)(424,482,510,
     538)(425,483,511,539)(426,484,512,540)(541,606,580,629)(542,554,576,626)
     (543,557,579,628)(544,607,643,649)(545,578,627,547)(546,596)(548,588,633,
     561)(549,608,550,609)(551,610,577,571)(552,611,575,625)(553,559,572,586)
     (555,612,592,636)(556,613,593,637)(558,614,644,650)(560,615,587,603)(562,
     616,582,598)(563,617,583,599)(564,618,589,605)(565,619,590,634)(566,620,
     581,630)(567,595,584,631)(568,594,585,632)(569,621,645,651)(570,622,597,
     638)(573,623,600,639)(574,624)(591,635,646,652)(601,640,647,653)(602,641,
     648,654)(604,642)(655,681,703,712)(656,682,704,713)(657,683)(658,684,665,
     691)(659,685,674,697)(660,686,673,670)(661,687,705,714)(662,688,706,715)
     (663,689,707,716)(664,690,676,699)(666,692)(667,693,668,694)(669,677,675,
     698)(671,695,708,717)(672,696,709,718)(678,700,710,719)(679,701)(680,702,
     711,720)(721,722,723,733)(724,727,737,731)(725,741,749,753)(726,742,732,
     745)(728,743,750,754)(729,744,735,746)(730,736,734,738)(739,747,751,755)
     (740,748,752,756);