b21 := (1,49,14,37,74)(2,16,52,96,44)(3,99,38,18,61)(5,62,64,65,95)(6,8,40,85,
     58)(7,68,80,9,39)(10,19,31,97,72)(11,77,93,84,98)(12,46,86,78,42)(13,23,
     54,29,15)(17,82,69,34,30)(21,28,56,88,89)(22,100,73,87,35)(24,79,67,59,
     32)(25,43,27,66,75)(26,92,47,50,94)(33,36,57,70,81)(41,83,55,91,51)(45,
     90,60,48,71);