z1 := (1,3,4)(2,5,6)(7,11,12)(8,13,14)(9,15,16)(10,17,18)(19,25,26)(20,27,28)
     (21,29,30)(22,31,32)(23,33,34)(24,35,36)(37,40,45)(38,39,46)(41,44,47)
     (42,43,48);