z1 := (3,5)(4,6)(7,11)(8,13)(9,14)(10,16)(12,19)(15,23)(17,25)(20,28)(21,29)
     (22,31)(24,33)(26,36)(27,37)(30,42)(32,45)(34,48)(35,50)(38,55)(40,57)
     (41,59)(43,61)(44,63)(46,66)(47,68)(49,71)(51,73)(52,75)(53,76)(54,78)
     (56,81)(58,64)(60,84)(62,86)(65,89)(67,74)(69,94)(70,96)(77,103)(79,105)
     (80,107)(82,108)(83,110)(85,113)(87,115)(88,116)(90,117)(91,119)(92,120)
     (93,122)(95,111)(97,126)(98,127)(99,129)(100,130)(102,131)(104,133)(106,
     136)(109,138)(112,132)(114,142)(118,146)(121,124)(123,149)(125,151)(135,
     137)(140,154)(141,160)(144,161)(145,163)(147,152)(148,165)(150,166)(153,
     157)(156,169)(158,164)(167,174)(168,172)(170,176);