diff --git a/tests/test_introduction.py b/tests/test_introduction.py
index 93e724b..fca3263 100644
--- a/tests/test_introduction.py
+++ b/tests/test_introduction.py
@@ -15,7 +15,7 @@
 class TestIntroductory:
     @pytest.fixture
     def user_list(self):
-        return ["Zain-Mahmoud", "kurbydoo", "mouftz"]
+        return ["Zain-Mahmoud", "kurbydoo", "mouftz", "yh-cyber"]
 
     def test_kurbydoo(self, user_list):
         assert 1 + 1 == 2, "Somthing went really wrong"
@@ -27,7 +27,7 @@ def test_kurbydoo(self, user_list):
 
         assert counter == n * (n - 1) // 2, "Check arithmetic sum"
 
-        assert len(user_list) == 3
+        assert len(user_list) == 4
 
     ### Add your tests below, follow the format above
 
@@ -41,3 +41,6 @@ def test_Zain_Mahmoud(self, user_list):
 
     def test_mouftz(self, user_list):
         assert "racecar" == "racecar"[::-1], "Check palindrome"
+
+    def test_yh_cyber(self, user_list):
+        assert sum([1, 2, 3]) == 6, "Check sum"