b := (  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17)
( 18, 34, 49, 63, 76, 88, 99,109,118,126,133,139,144,148,151,153, 33)
( 19, 35, 50, 64, 77, 89,100,110,119,127,134,140,145,149,152, 32, 48)
( 20, 36, 51, 65, 78, 90,101,111,120,128,135,141,146,150, 31, 47, 62)
( 21, 37, 52, 66, 79, 91,102,112,121,129,136,142,147, 30, 46, 61, 75)
( 22, 38, 53, 67, 80, 92,103,113,122,130,137,143, 29, 45, 60, 74, 87)
( 23, 39, 54, 68, 81, 93,104,114,123,131,138, 28, 44, 59, 73, 86, 98)
( 24, 40, 55, 69, 82, 94,105,115,124,132, 27, 43, 58, 72, 85, 97,108)
( 25, 41, 56, 70, 83, 95,106,116,125, 26, 42, 57, 71, 84, 96,107,117);