shell - extract the data from a text file without any delimiter or spaces and append it two file different files

Question

I have an input text file which appears like this,

12717251268292797123831987-->Header

a1921972998468104998676534716
17923862384623647864723467631
28791379370982379807821876843
23767891263716387928371836183
32189378913681698677676372876
28168961846349876479864210986

12541521---->tail

Now I want to split the above file in to two different text files.

Can anyone suggest me how to do it using unix shell script.

Answer 1

use

split -l 'number of lines' filename