b11 := (4,5)(6,8)(7,10)(12,18)(14,21)(16,23)(17,25)(19,28)(24,36)(30,45)(32,48)
     (33,50)(38,57)(42,61)(49,63)(55,77)(58,76)(59,83)(60,85)(65,91)(66,93)
     (71,97)(72,99)(74,101)(75,103)(86,116)(87,118)(89,121)(90,123)(102,141)
     (105,146)(107,148)(108,150)(111,154)(112,156)(113,145)(114,137)(117,162)
     (119,165)(125,140)(129,176)(130,178)(131,180)(132,152)(133,183)(135,186)
     (142,195)(143,196)(144,198)(149,205)(153,210)(155,214)(159,220)(166,230)
     (167,231)(168,233)(170,235)(173,238)(174,240)(175,242)(177,246)(182,243)
     (184,256)(185,258)(188,263)(190,266)(191,268)(199,223)(200,280)(206,262)
     (207,286)(208,288)(209,259)(217,298)(226,308)(232,312)(239,297)(247,327)
     (248,328)(249,330)(250,291)(251,332)(257,337)(260,341)(261,343)(264,346)
     (274,357)(283,364)(287,366)(290,371)(294,374)(295,375)(296,377)(301,382)
     (302,384)(304,387)(305,388)(306,383)(310,380)(311,342)(316,395)(320,399)
     (322,401)(323,402)(329,405)(331,367)(334,414)(338,418)(344,415)(347,423)
     (349,426)(350,427)(351,428)(352,400)(356,429)(359,424)(363,433)(370,439)
     (376,443)(381,447)(389,454)(431,475)(444,470)(446,479)(451,487)(452,473)
     (458,491)(465,471)(466,468)(467,476)(469,497)(478,502)(483,496)(485,501)
     (494,510)(499,508);