A zip file is given.
Unzip this archive and find the file named 'uber-secret.txt' Unzip the file.
unzip files.zipApplying find command to find the file.
find files -name 'uber-secret.txt'files/adequate_books/more_books/.secret/deeper_secrets/deepest_secrets/uber-secret.txt
Applying cat on the file gives the flag.
cat files/adequate_books/more_books/.secret/deeper_secrets/deepest_secrets/uber-secret.txtpicoCTF{f1nd_15_f457_ab443fd1}