diff --git a/.gitignore b/.gitignore
index 8907886..5281a53 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,6 +31,7 @@
 *.out
 *.app
 *.jar
+*.py
 
 # VS Code
 .vscode/
diff --git a/Exercise 5/Lexer.java b/Exercise 5/Lexer.java
new file mode 100644
index 0000000..d42595e
--- /dev/null
+++ b/Exercise 5/Lexer.java	
@@ -0,0 +1,9 @@
+public class Lexer {
+    Lexer(String src_in) {
+        System.out.println(src_in);
+    }
+
+    public void run() {
+        System.out.println("Lexer runs.");
+    }
+}
diff --git a/Exercise 5/LexerTestApp.java b/Exercise 5/LexerTestApp.java
new file mode 100644
index 0000000..0fe0208
--- /dev/null
+++ b/Exercise 5/LexerTestApp.java	
@@ -0,0 +1,9 @@
+public class LexerTestApp {
+    public static void main(String[] Args) {
+        // Meldung bei Programmaufruf
+        System.out.println("Lexer Test App.");
+
+        Lexer this_Lexer = new Lexer("index = 2 * count + 42;");
+        this_Lexer.run();
+    }
+}