I wrote a bash script to extract recursive archive and get the flag:

```
#/bin/bash
file="0.zip"
if [ -f "$file" ]; then
for i in {1..1650}; do
7z e ${file} > /dev/null;
file=`7z l ${file}|grep -Eo "[0-9]{1,4}\.(tar$|tar\.bz2$|zip$|kz3$|kz2$|tar\.gz$)"|tail -1`;
echo "${file} num:$i";
done
fi
find ./ -name "*.txt" -exec cat {} \; |uniq
```