diff --git a/String calculator b/String calculator
index 9c8f5f2faa5c1cf9894cd1fb5653481c47c010f7..dc49d13bb6407c58be02174f1b56052324ae286d 100644
--- a/String calculator	
+++ b/String calculator	
@@ -17,11 +17,12 @@ class StringCalculator:
         if not numbers:
             return 0
         else:
-            numbers = numbers.replace('\n',',')#aufteilung der strings
-            number_list = numbers.split(',')
+            numbers = numbers.replace('\n',',')
+            number_list = numbers.split(',')#aufteilung der strings
             total_sum = 0
             for number_str in number_list: #jedes element in der liste wird durch genommen
-                total_sum += int(number_str)# summierung der integer
+                if number_str:
+                    total_sum += int(number_str)# summierung der integer
             return total_sum 
         
     
@@ -44,6 +45,8 @@ class TestStingCalculator(unittest.TestCase):
     def test_numbers_seperated_by_newline(self):
         calculator=StringCalculator()
         self.assertEqual(calculator.add("1\n2"),3)
+        self.assertEqual(calculator.add("1\n2\n3"),6)
+        self.assertEqual(calculator.add("10,20\n30"),60)
 
 if __name__=='__main__':
     unittest.main()
\ No newline at end of file