z1 := (1,2)(3,5)(4,7)(6,10)(9,14)(11,17)(12,19)(13,20)(15,23)(16,25)(18,28)
     (21,33)(26,39)(27,41)(29,44)(30,46)(32,48)(34,51)(35,52)(36,54)(37,55)
     (38,57)(40,60)(42,63)(43,65)(45,68)(47,64)(49,72)(50,74)(53,77)(56,82)
     (58,85)(59,86)(61,89)(62,91)(66,95)(67,97)(69,100)(70,101)(71,103)(73,
     104)(75,107)(76,108)(78,111)(79,113)(80,114)(81,116)(83,119)(84,121)(87,
     126)(88,128)(90,131)(92,134)(93,136)(94,137)(96,139)(98,142)(99,144)(102,
     149)(105,153)(106,154)(109,159)(110,161)(115,168)(117,171)(118,173)(120,
     176)(122,148)(123,178)(124,179)(125,181)(127,143)(129,186)(130,188)(132,
     189)(133,191)(135,194)(138,198)(140,200)(141,202)(145,207)(146,209)(147,
     210)(150,212)(152,205)(155,215)(156,217)(157,218)(158,220)(160,172)(162,
     225)(163,227)(165,229)(166,230)(167,232)(170,235)(174,239)(175,241)(177,
     244)(180,248)(182,250)(183,252)(184,253)(185,255)(187,258)(190,261)(193,
     264)(195,267)(196,269)(197,270)(203,238)(204,274)(206,275)(208,278)(211,
     283)(213,286)(214,287)(216,289)(219,265)(221,291)(222,292)(223,293)(224,
     295)(226,297)(228,284)(231,304)(233,262)(234,307)(236,310)(237,312)(242,
     263)(243,314)(245,296)(246,317)(247,319)(249,277)(251,323)(254,325)(256,
     328)(257,301)(259,273)(260,332)(268,337)(271,306)(272,340)(279,345)(280,
     346)(281,347)(282,349)(285,352)(288,355)(290,358)(294,362)(298,367)(299,
     369)(302,329)(303,371)(305,374)(308,377)(309,379)(313,383)(315,331)(318,
     387)(320,389)(321,390)(322,392)(324,368)(326,397)(327,398)(330,399)(333,
     401)(334,403)(335,342)(336,405)(338,360)(339,381)(341,388)(343,375)(344,
     391)(348,412)(350,415)(351,416)(353,407)(354,365)(356,419)(357,421)(361,
     408)(363,395)(364,423)(366,424)(370,425)(372,426)(373,427)(376,386)(378,
     430)(380,410)(382,394)(384,432)(385,433)(393,435)(396,413)(400,402)(404,
     440)(409,411)(414,418)(417,446)(422,448)(436,437)(438,454)(439,456)(441,
     455)(442,457)(443,453)(444,458)(445,449)(452,460);