Unlike other participants, I could not just make `find` work for me, so I had to find another way.

Fortunately, there's a very nice tool called `fatcat `. It can show directory listing without mounting an image, and it also shows "real" inodes:

```
% fatcat -l / strcmp.fat32
Listing path /
Directory cluster: 2
d 1/1/1980 00:00:00 SPACE/ c=758
d 1/1/1980 00:00:00 !/ c=1406
d 1/1/1980 00:00:00 #/ c=1618
d 1/1/1980 00:00:00 $/ c=1254
d 1/1/1980 00:00:00 %/ c=1406
d 1/1/1980 00:00:00 &/ c=1618
...
```

So the procedure was:

* Create a blacklist of "invalid" inodes. It's very easy, because we know that flag starts with "PCTF{"
* Just go level down until the flag is complete ignoring directories that link to blacklisted inodes.

Creating a blacklist of inodes (also had to add some manually):

```
for symbool in $(cat all-symbols); do fatcat strcmp.fat32 -l "/$symbol" | awk '{print $5}' | cut -d= -f2 | grep -v '^$'; done | sort | uniq >> bad-inodes
```

Creating regexp list:

```
cat bad-inodes | sort | uniq | while read s; do echo 'c='$s'$'; done > r
```

Final iterating looked like this:

```
% fatcat strcmp.fat32 -l '/P/C/T/F/{/W/H/A/T/_/I/N/_/T/A/R/N/A/T/I/O/N/_/I/S/_/T/H/1/S/_/F/I/L/E/' | grep -vf r

Listing path /P/C/T/F/{/W/H/A/T/_/I/N/_/T/A/R/N/A/T/I/O/N/_/I/S/_/T/H/1/S/_/F/I/L/E/
Directory cluster: 950
d 1/1/1980 00:00:00 P/ c=1110
d 1/1/1980 00:00:00 S/ c=1454
f 1/1/1980 00:00:00 TOOBAD c=1842 s=0 (0B)
% fatcat strcmp.fat32 -l '/P/C/T/F/{/W/H/A/T/_/I/N/_/T/A/R/N/A/T/I/O/N/_/I/S/_/T/H/1/S/_/F/I/L/E/S/' | grep -vf r

Listing path /P/C/T/F/{/W/H/A/T/_/I/N/_/T/A/R/N/A/T/I/O/N/_/I/S/_/T/H/1/S/_/F/I/L/E/S/
Directory cluster: 1454
d 1/1/1980 00:00:00 P/ c=1110
d 1/1/1980 00:00:00 Y/ c=622
f 1/1/1980 00:00:00 NOMATCH c=1842 s=0 (0B)

....
% fatcat strcmp.fat32 -l '/P/C/T/F/{/W/H/A/T/_/I/N/_/T/A/R/N/A/T/I/O/N/_/I/S/_/T/H/1/S/_/F/I/L/E/S/Y/S/T/E/M/!/}/' | grep -vf r

Listing path /P/C/T/F/{/W/H/A/T/_/I/N/_/T/A/R/N/A/T/I/O/N/_/I/S/_/T/H/1/S/_/F/I/L/E/S/Y/S/T/E/M/!/}/
Directory cluster: 1638
```

The challenge was generated with this tool: https://github.com/8051Enthusiast/regex2fat