a11 := (1,2)(3,5)(4,7)(6,9)(8,12)(10,14)(11,15)(13,18)(16,21)(17,23)(19,26)(20,
     28)(22,29)(24,31)(25,33)(27,35)(30,37)(32,40)(34,43)(36,45)(38,41)(39,47)
     (42,51)(44,53)(46,55)(48,58)(49,54)(50,56)(52,59)(57,61)(60,62);