diff --git a/Week04/functions_mert_durgun.py b/Week04/functions_mert_durgun.py
new file mode 100644
index 00000000..0b4313a9
--- /dev/null
+++ b/Week04/functions_mert_durgun.py
@@ -0,0 +1,28 @@
+custom_power = lambda x=0,/,e=1 : x**e
+
+def custom_equation(x: int = 0, y: int = 0, /, a: int = 1, b: int = 1, *, c: int = 1) -> float:
+    """
+    :param x: The positional-only integer base for the first term, default is 0
+    :param y: The positional-only integer base for the second term, default is 0
+    :param a: The positional-or-keyword integer exponent for the first term, default is 1
+    :param b: The positional-or-keyword integer exponent for the second term, default is 1
+    :param c: The keyword-only integer divisor, default is 1
+    :return: The result of the calculation as a float
+    :rtype: float
+    """
+    return (x**a + y**b) / c
+
+
+
+
+def fn_w_counter() -> (int, dict[str, int]):
+    if not hasattr(fn_w_counter, "counter"):
+        fn_w_counter.counter = 0
+        fn_w_counter.dict = {}
+    caller_name = __name__
+    fn_w_counter.counter += 1
+    if caller_name in fn_w_counter.dict:
+        fn_w_counter.dict[caller_name] += 1
+    else:
+        fn_w_counter.dict[caller_name] = 1
+    return fn_w_counter.counter, fn_w_counter.dict