diff --git a/converter.py b/converter.py
new file mode 100644
index 0000000000000000000000000000000000000000..0ef9bd00dc3c5f4bb6eec9d95b79aea454ffd3f8
--- /dev/null
+++ b/converter.py
@@ -0,0 +1,49 @@
+#Bei Eingabe von Zahlen, die in der Liste definiert sind, sollen römische Zhalen zurückgegeben werden.
+#Bei Eingabe von Zahlen, die nicht in der Liste definiert ist, soll ein "" ausgeben werden.
+
+import unittest
+from abc import ABC, abstractmethod
+
+class IRomanNumber(ABC):
+    @abstractmethod
+    def convert(self, n:int) -> str:
+        pass
+
+class RomanNumber(IRomanNumber):
+    def convert(self, n: int) -> str:
+        roman_numerals = {
+            1: "I",  2: "II", 3: "III", 
+            4: "IV",  5: "V", 9: "IX", 
+            21: "XXI",  50: "L", 100: "C",
+            500: "D",  1000: "M" 
+        }
+        return roman_numerals.get(n, "")
+
+class TestRomanConverter(unittest.TestCase):
+    def setUp(self):
+        self.converter = RomanNumber()
+
+    def test_single_value(self):
+        self.assertEqual(self.converter.convert(1), "I")
+        self.assertEqual(self.converter.convert(2), "II")
+        self.assertEqual(self.converter.convert(3), "III")
+        self.assertEqual(self.converter.convert(4), "IV")
+        self.assertEqual(self.converter.convert(5), "V")
+        self.assertEqual(self.converter.convert(9), "IX")
+        self.assertEqual(self.converter.convert(21), "XXI")
+        self.assertEqual(self.converter.convert(50), "L")
+        self.assertEqual(self.converter.convert(100), "C")
+        self.assertEqual(self.converter.convert(500), "D")
+        self.assertEqual(self.converter.convert(1000), "M")
+    
+    def test_inivalid_numbers(self):
+        self.assertEqual(self.converter.convert(6), "")
+        self.assertEqual(self.converter.convert(99), "")
+        self.assertEqual(self.converter.convert(-1), "")
+        
+
+
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/hello.py b/hello.py
deleted file mode 100644
index 6d95fe97a12449aa7e3cf570dea13203d07571b9..0000000000000000000000000000000000000000
--- a/hello.py
+++ /dev/null
@@ -1 +0,0 @@
-print("Hello world")
\ No newline at end of file