Download entire website directory structure, without downloading any file contents

Need to download the entire website tree structure with directory/files names, but without download files - just structure. like this:

www.example.com
 |
  dir1
   | file1.txt
     file2.txt

  dir2
   | file3.txt
   | file4.txt

When I use wget --mirror it downloas files

wget --mirror  http://www.example.com