Error applying 'chmod' command

Hello,

As it was not possible to write in any of the documents, I had "permission only to read", I looked for information on the internet ... and after:

Code:ken@rosa-ry9zph ~ $ ls -l
total 32
drwxr-xr-x 9 ken ken 4096 Jul 26 09:58 Downloads
drwxr-xr-x 8 ken ken 4096 Jul 26 06:20 Documents
drwxr-xr-x 2 ken ken 4096 Jul 22 11:53 Desktops
drwxr-xr-x 3 ken ken 4096 Jul 26 06:33 Images
drwxr-xr-x 2 ken ken 4096 Jul 22 08:22 Music
drwxr-xr-x 2 ken ken 4096 Jul 25 16:48 Templates
drwxr-xr-x 2 ken ken 4096 Jul 22 08:22 Public
-rw-r--r--r-- 1 ken ken 0 jul 26 07:40 test
drwxr-xr-x 2 ken ken 4096 Jul 22 08:22 Videos
ken@rosa-ry9zph ~ $I think I carelessly applied the command as root:

Code:# chmod -R 420 /home/ken/Documents/Chess[although I tried to do it as "$", with another file, and it denied me the permission (?)].

Now I can only access to the files I have in "Chess" only as root.

I don't know what else to do and I don't want to make a worse mistake, so I would be very grateful if someone could tell me how to solve this situation.

Best regards.