z1 := (1,2)(3,4)(5,7)(6,8)(9,11)(10,12)(13,15)(14,17)(16,20)(18,22)(19,23)(21,
     26)(24,30)(25,31)(28,34)(29,36)(32,40)(33,41)(35,44)(37,46)(38,47)(39,49)
     (42,53)(43,54)(45,57)(48,61)(50,63)(51,64)(52,66)(55,70)(56,71)(58,74)
     (59,75)(60,77)(62,80)(65,84)(67,86)(68,87)(69,89)(72,93)(73,94)(76,98)
     (78,100)(79,101)(81,104)(82,105)(83,107)(85,109)(88,113)(90,115)(91,116)
     (92,118)(95,122)(96,123)(97,125)(99,128)(102,132)(103,133)(106,137)(108,
     139)(110,112)(111,140)(114,144)(119,149)(120,150)(121,152)(124,156)(126,
     142)(127,158)(129,161)(130,162)(131,157)(134,167)(135,168)(136,170)(138,
     173)(141,163)(143,177)(145,180)(146,181)(147,183)(148,185)(153,190)(154,
     191)(155,193)(159,198)(160,199)(164,203)(165,204)(166,206)(169,210)(171,
     211)(172,212)(174,215)(175,216)(176,217)(178,220)(179,221)(182,224)(184,
     226)(186,228)(187,229)(188,230)(189,231)(192,235)(194,237)(195,238)(196,
     240)(197,241)(200,244)(201,209)(202,246)(205,250)(207,252)(208,253)(213,
     259)(214,260)(218,265)(219,266)(222,270)(223,271)(225,274)(227,277)(232,
     251)(233,281)(234,283)(236,285)(239,289)(242,292)(245,268)(247,296)(248,
     297)(249,299)(254,304)(255,305)(256,306)(258,262)(261,312)(263,291)(264,
     315)(267,319)(269,321)(272,325)(273,326)(275,328)(276,329)(278,332)(279,
     333)(280,335)(282,337)(284,294)(286,341)(287,342)(288,344)(290,309)(293,
     349)(295,351)(298,353)(300,354)(301,355)(302,356)(303,357)(307,360)(308,
     361)(310,362)(311,364)(313,367)(314,368)(316,370)(317,371)(318,373)(320,
     322)(323,376)(324,378)(327,382)(330,385)(331,386)(334,389)(336,390)(338,
     391)(339,365)(340,393)(343,396)(345,398)(346,399)(347,401)(348,402)(350,
     375)(358,409)(359,410)(363,415)(366,416)(369,420)(372,422)(374,424)(377,
     411)(379,428)(380,429)(381,430)(383,387)(384,423)(388,436)(392,440)(394,
     442)(395,412)(397,444)(400,446)(403,448)(404,449)(405,451)(406,452)(407,
     453)(413,458)(414,459)(417,435)(418,456)(419,460)(421,437)(425,468)(426,
     469)(427,470)(431,450)(432,474)(433,476)(434,477)(438,480)(439,475)(441,
     481)(443,467)(445,465)(447,483)(454,457)(455,487)(461,464)(462,486)(463,
     490)(466,478)(471,488)(472,493)(473,494)(479,497)(482,489)(484,499)(485,
     500)(491,501)(492,498)(495,496)(502,503)(504,513)(505,514)(507,511)(508,
     515)(509,517)(510,512)(516,519)(518,520);