[1,2,3,2,3,4,5,4,5,4,6,7,6,7,6,8,6,8,9,8,9,8,9,10, 11,10,11,10,12,10,12,13,12,13,12,14,12,14,12,14, 15,14,15,16,15,16,15,16,17,16,17,16,18,19,18,19, 18,20,18,20,18,20,18,20,21,20,21,20,21,22,21]