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