z1 := (2,3)(4,6)(5,7)(8,11)(9,12)(10,14)(13,18)(15,20)(16,21)(17,23)(19,25)
     (22,28)(24,30)(26,32)(29,36)(31,39)(33,42)(34,43)(35,44)(37,47)(38,48)
     (40,51)(41,52)(45,57)(46,58)(49,62)(50,63)(53,67)(54,68)(55,70)(56,72)
     (59,76)(60,77)(61,79)(64,83)(65,84)(66,86)(69,90)(71,92)(73,94)(74,95)
     (75,97)(78,101)(80,103)(81,104)(82,106)(85,110)(87,112)(88,113)(89,115)
     (91,118)(96,123)(98,125)(99,126)(100,128)(102,131)(105,134)(107,136)(109,
     138)(111,141)(114,145)(116,147)(119,150)(120,151)(121,153)(122,154)(124,
     157)(127,161)(129,163)(130,164)(132,167)(133,169)(135,172)(137,175)(139,
     176)(140,177)(142,180)(143,181)(144,183)(146,186)(148,189)(149,190)(152,
     194)(155,197)(156,198)(158,201)(159,185)(160,203)(162,206)(165,209)(166,
     210)(168,212)(170,214)(171,215)(173,218)(174,193)(178,217)(179,221)(182,
     225)(184,227)(187,230)(188,231)(191,235)(192,236)(195,200)(196,241)(199,
     245)(202,248)(204,250)(205,251)(207,254)(208,255)(211,259)(213,260)(216,
     263)(219,266)(220,267)(222,265)(223,270)(224,272)(226,275)(228,277)(229,
     278)(232,282)(234,284)(237,287)(238,288)(239,289)(240,291)(242,293)(243,
     294)(244,296)(246,298)(247,299)(249,302)(253,305)(256,309)(257,310)(258,
     312)(261,315)(262,316)(264,318)(268,322)(269,323)(271,325)(273,327)(274,
     281)(276,330)(279,334)(280,335)(283,337)(285,339)(286,340)(290,344)(292,
     345)(295,349)(297,351)(300,354)(301,355)(303,357)(304,336)(306,360)(307,
     361)(308,362)(311,366)(313,368)(314,369)(317,373)(319,375)(320,348)(321,
     377)(324,380)(326,382)(328,346)(329,385)(331,388)(332,389)(333,391)(338,
     395)(341,399)(342,400)(343,402)(347,406)(350,410)(352,412)(353,414)(356,
     417)(358,359)(363,423)(364,424)(365,401)(367,428)(370,392)(371,432)(372,
     434)(374,379)(376,437)(378,426)(381,441)(383,443)(384,411)(386,390)(387,
     445)(393,449)(394,450)(396,403)(397,451)(398,453)(404,457)(405,459)(407,
     462)(408,463)(409,464)(415,438)(416,468)(418,461)(419,471)(420,452)(421,
     473)(422,472)(425,477)(427,478)(430,481)(433,482)(435,484)(436,486)(439,
     489)(440,490)(442,493)(444,456)(446,496)(447,497)(448,494)(454,485)(455,
     501)(458,503)(460,492)(465,507)(466,509)(467,510)(469,476)(474,513)(475,
     506)(479,516)(480,517)(483,495)(487,522)(488,523)(491,502)(498,508)(499,
     530)(500,531)(504,528)(505,529)(511,535)(512,536)(514,537)(515,538)(518,
     524)(519,540)(520,541)(521,543)(525,532)(527,533)(534,549)(539,548)(542,
     545)(544,554)(547,552)(551,558)(553,559)(555,556);