diff --git a/atom.py b/atom.py
new file mode 100644
index 0000000..6f383ac
--- /dev/null
+++ b/atom.py
@@ -0,0 +1,2 @@
+class Atom:
+	pass
\ No newline at end of file
diff --git a/lisp.py b/lisp.py
new file mode 100644
index 0000000..275f0a3
--- /dev/null
+++ b/lisp.py
@@ -0,0 +1,5 @@
+import atom
+
+class Lisp:
+	def evaluate(self, expression: str):
+		return expression.upper()
\ No newline at end of file
diff --git a/repl.py b/repl.py
new file mode 100644
index 0000000..0248b5c
--- /dev/null
+++ b/repl.py
@@ -0,0 +1,12 @@
+import lisp
+
+def main():
+	print("Welcome message.")
+	state = lisp.Lisp()
+	# REPL Loop
+	while True:
+		expression: str = input("> ")
+		print(state.evaluate(expression))
+
+if __name__ == "__main__":
+	main()
\ No newline at end of file