```#!/bin/bash
while [[ true ]]; do	if [[ -f flag.txt ]] 	then		file="flag.txt"  		sign=`xxd flag.txt | head -n 1 | awk '{print $2}'`	else		file="flag"		sign=`xxd flag | head -n 1 | awk '{print $2}'`	fi	if [[ $sign == "fd37"  ]]	then		mv $file flag.7z		p7zip -d flag.7z	elif [[ $sign == "1f8b" ]]	then		mv $file flag.gz		gzip -d flag.gz	elif [[ $sign == "504b" ]]	then		mv $file flag.zip		unzip flag.zip		rm flag.zip	elif [[ $sign == "425a" ]]	then		mv $file flag.bz2		bzip2 -d flag.bz2	else		cat flag | base64 -d		exit 1	fidone```