require 'date'
file = "UTF_06012018_SAMPLE_Control.xlsx\nUTF_06022018_SAMPLE_Control.xlsx\nUTF_06092018_SAMPLE_Control.xlsx\nUTF_06022018_SAMPLE_Control.xlsx\nUTF_06082018_SAMPLE_Control.xlsx  \nUTF_06032018_SAMPLE_Demand.xlsx               \nUTF_06092018_SAMPLE_Demand.xlsx  \nUTF_06122018_SAMPLE_Demand.xlsx\nUTF_06032018_SAMPLE_Control.xlsx\nUTF_06022018_SAMPLE_Demand.xlsx"
puts file.scan(/^([^_]*_(\d++)(.*))/).sort_by { |m,n,z| [n.to_i,z] }.collect{ |m,n,z| m}.join("\n")

cmVxdWlyZSAnZGF0ZScKZmlsZSA9ICJVVEZfMDYwMTIwMThfU0FNUExFX0NvbnRyb2wueGxzeFxuVVRGXzA2MDIyMDE4X1NBTVBMRV9Db250cm9sLnhsc3hcblVURl8wNjA5MjAxOF9TQU1QTEVfQ29udHJvbC54bHN4XG5VVEZfMDYwMjIwMThfU0FNUExFX0NvbnRyb2wueGxzeFxuVVRGXzA2MDgyMDE4X1NBTVBMRV9Db250cm9sLnhsc3ggIFxuVVRGXzA2MDMyMDE4X1NBTVBMRV9EZW1hbmQueGxzeCAgICAgICAgICAgICAgIFxuVVRGXzA2MDkyMDE4X1NBTVBMRV9EZW1hbmQueGxzeCAgXG5VVEZfMDYxMjIwMThfU0FNUExFX0RlbWFuZC54bHN4XG5VVEZfMDYwMzIwMThfU0FNUExFX0NvbnRyb2wueGxzeFxuVVRGXzA2MDIyMDE4X1NBTVBMRV9EZW1hbmQueGxzeCIKcHV0cyBmaWxlLnNjYW4oL14oW15fXSpfKFxkKyspKC4qKSkvKS5zb3J0X2J5IHsgfG0sbix6fCBbbi50b19pLHpdIH0uY29sbGVjdHsgfG0sbix6fCBtfS5qb2luKCJcbiIp