diff --git a/.gitignore b/.gitignore
index defb60e..5e3aa4e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -159,10 +159,6 @@ cython_debug/
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 #.idea/
 
+# adminstration
 .DS_Store
-.vscode
-
-ecosystem/
-scratch_pad/
-journal/
-applications/
+todo.txt
\ No newline at end of file
diff --git a/.spellcheck_exceptions_dictionary.txt b/.spellcheck_exceptions_dictionary.txt
index 23d95c0..40f5efd 100644
--- a/.spellcheck_exceptions_dictionary.txt
+++ b/.spellcheck_exceptions_dictionary.txt
@@ -1,4 +1,5 @@
 # acronyms
+ACM
 CRLF
 LF
 DLR
@@ -16,6 +17,7 @@ AMI
 FPM
 GC
 
+
 # authors
 Rossum
 praisetompane
@@ -28,6 +30,7 @@ Marangon
 
 
 # domain specific
+Multiparadigm
 radix
 bytecode
 whitespace
@@ -60,6 +63,7 @@ metaclass
 
 
 # python keywords:
+stdin
 pprint
 getitem
 stdtypes
diff --git a/1_core_language/1_implementations/0_def.txt b/1_core_language/1_implementations/0_def.txt
index 2232509..686bb08 100644
--- a/1_core_language/1_implementations/0_def.txt
+++ b/1_core_language/1_implementations/0_def.txt
@@ -1,5 +1,5 @@
 - known implementations (Python Software Foundation, 2023):
-    - CPython:	Original and First Python. 
+    - CPython:	Original and First Python.
                 Implementations in C.
                 Compiles/Interprets to machine code.
 
@@ -24,6 +24,7 @@
     - Brython: https://github.com/brython-dev/brython
 
     - Cython: https://github.com/cython/cython
+
 - ports:
     - Pyodide: https://github.com/pyodide/pyodide
         - platform:
diff --git a/README.md b/README.md
index 53789ec..cf0b8f2 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,9 @@
             - They are prefixed with "Praise:"
     - Python's design, implementation and ecosystem.
 
+## ACM Classification:
+Software And Its Engineering/Software Notations And Tools/General Programming Languages/Language Types/Multiparadigm Languages
+
 ## Language Details
 - Language Specification: None
 - [Interpreter](https://github.com/python/cpython)
@@ -22,8 +25,8 @@
 - [Memory Model](https://ocw.mit.edu/courses/6-006-introduction-to-algorithms-fall-2011/pages/readings/python-cost-model/)
 - [Language Reference](https://docs.python.org/3/reference/index.html)
 - [Standard Library](https://docs.python.org/3/library/index.html)
-- [Packaging and Distribution]( https://www.pypa.io/en/latest/)
     - [Core Module Index](https://docs.python.org/3/py-modindex.html)
+- [Packaging and Distribution]( https://www.pypa.io/en/latest/)
     - [Package Index](https://pypi.org)
     - Tools:
         - [pip](https://pip.pypa.io/en/stable/)
@@ -55,6 +58,13 @@
 pyspelling -c spellcheck.yaml
 ```
 
+## Execute Programs
+```shell
+python source_file.py
+#Example:
+python 4_experiments/2_standard_library/2_builtin_functions/io/input_stdin.py
+```
+
 # References
 
 ## Legend:
diff --git a/ecosystem/scientific_and_numeric/empty_file b/ecosystem/scientific_and_numeric/empty_file
new file mode 100644
index 0000000..e69de29
diff --git a/ecosystem/testing/empty_file b/ecosystem/testing/empty_file
new file mode 100644
index 0000000..e69de29
diff --git a/ecosystem/web_and_internet_development/http/empty_file b/ecosystem/web_and_internet_development/http/empty_file
new file mode 100644
index 0000000..e69de29
diff --git a/ecosystem/web_and_internet_development/servers/empty_file b/ecosystem/web_and_internet_development/servers/empty_file
new file mode 100644
index 0000000..e69de29