破解字符串對應的md5sum前的RANDOM對應數字

已知下面的字符串是通過RANDOM隨機數變量md5sum|cut-c 1-8截取後的結果，請破解這些字符串對應的md5sum前的RANDOM對應數字？
21029299
00205d1c
a3da1677
1f6d12dd
腳本如下：
#!/bin/sh
#######################################################
#ShellName:crack random
#Author:zkg
#Created Time:2019-08-29
#Blog Address:https://blog.51cto.com/1009516
#######################################################

#引用系統函數庫
. /etc/init.d/functions

#定義數組
md5sumafter=(21029299 00205d1c a3da1677 1f6d12dd)

for randomnum in {0..32767}
do
randommd5sum=echo $randomnum |md5sum|cut -c 1-8
for ((i=0;i<${#md5sumafter[*]};i++))
do
if [ "${md5sumafter[i]}" == "$randommd5sum" ];then
echo -e "$randomnum\t $randommd5sum" >> /opt/shell/random.txt
echo -e "$randomnum\t $randommd5sum"
fi
done
done
action "字符串破解完成！！！" /bin/true