Output count of files which start with upper case letter and doesn't contain any other upper case letter

Author: hamdiheb

shell-pipelines/ls-grep/script-04.sh

@@ -3,4 +3,5 @@
 set -euo pipefail
 
 # TODO: Write a command to count the number of files in the sample-files directory whose name starts with an upper case letter and doesn't contain any other upper case letters.
+ls sample-files | grep -c '^[A-Z][^A-Z]*$'
 # Your output should be the number 7.