b11 := (2,4)(3,5)(6,8)(7,9)(10,14)(11,15)(13,16)(17,23)(18,24)(19,25)(21,26)
     (22,27)(28,35)(29,36)(30,37)(31,38)(32,39)(33,40)(34,41)(42,50)(43,47)
     (44,52)(45,51)(48,53)(49,54)(55,56);