z1 := (1,2)(3,7)(4,8)(5,9)(6,10)(11,19)(12,20)(13,21)(14,15)(16,22)(17,23)(18,
     24)(25,37)(26,38)(27,39)(28,40)(29,41)(30,42)(31,43)(32,44)(33,45)(34,46)
     (35,47)(36,48)(49,69)(50,60)(51,70)(52,71)(53,59)(54,68)(55,67)(56,64)
     (57,63)(58,72)(61,73)(62,74)(65,75)(66,76)(77,83)(78,82)(79,81)(80,84);