z1 := (2,4)(3,6)(5,10)(7,14)(9,17)(11,21)(12,23)(15,28)(22,37)(29,46)(34,50)
     (38,56)(42,61)(57,78)(58,79)(60,82)(63,87)(65,90)(67,71)(68,94)(70,95)
     (72,98)(74,84)(75,101)(80,109)(85,107)(89,118)(110,136)(111,137)(112,139)
     (115,141)(116,129)(120,145)(124,148)(138,158)(140,161)(142,164)(143,155)
     (150,170)(159,178)(162,181)(166,180)(171,188)(184,193)(189,203);