z1 := (1,2,5,3)(4,7,11,8)(6,10)(9,13)(12,14,17,15)(16,19,24,20)(18,21,26,22)
     (23,28,35,29)(25,30,38,31)(27,32,40,33)(34,41)(37,43)(39,45,42,46)(44,47,
     49,48);