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