awk目录序列的最大值

I'm trying to find the maximum value in a directory suffix using awk. The directories are named: dir.{1,2,3,4,5,6,7,8,9,10,11,12,13,etc}. My best attempts keep returning "9" as the highest value, probably due to it listing after the 'teens.I'm trying to find the maximum value in a direc