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