Write a shell script in bash doing the following task: search for all the files whose name ends with '.jpg' under the home directory, including all the subdirectories within; create a subdirectory called backup under the home directory; make a copy of all the .jpg files in backup or only the first 100 in case the total number is larger than 100; print a message reporting the job is done and saying "Take more pictures!" if the number of files copied is less than 5.

Hint: you probably need to use the commands wc and head; you may also need to use find. If you cannot get it work for 'all the subdirectories', try to create a simpler version only for the files directly in the home directory.