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