diff --git "a/Test_Converter_R\303\266mische_Zahlen.py" "b/Test_Converter_R\303\266mische_Zahlen.py"
index 8c05a93fb4475b3cb24c3decd882ec6d173f6b82..25edb99f94c556338857bbeca2f77301fceb8906 100644
--- "a/Test_Converter_R\303\266mische_Zahlen.py"
+++ "b/Test_Converter_R\303\266mische_Zahlen.py"
@@ -3,11 +3,13 @@
 import unittest
 
 def convert(n: int) -> str:
-    if n == 1:
-        return "I"
-    if n == 10:
-        return "X"
-    return ""
+    roman_numerals = {10: "X", 1: "I"}
+    result = ""
+    for value in sorted(roman_numerals.keys(), reverse=True):
+        while n >= value:
+            result += roman_numerals[value]
+            n -= value
+    return result
 
 class TestRomanConverter(unittest.TestCase):
     def test_1(self):
@@ -15,6 +17,8 @@ class TestRomanConverter(unittest.TestCase):
 
     def test_10(self):
         self.assertEqual(convert(10), "X")  # Erwartet "X" für 10
+    def test_21(self):
+        self.assertEqual(convert(21), "XXI")  # Erwartet "XXI" für 21
 
 if __name__ == "__main__":
     unittest.main()
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