diff --git a/Week04/functions_kerimcan_dede.py b/Week04/functions_kerimcan_dede.py
new file mode 100644
index 00000000..16bf3bc1
--- /dev/null
+++ b/Week04/functions_kerimcan_dede.py
@@ -0,0 +1,27 @@
+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:
+    """
+    This function does arithmetic opearations.
+
+    :param1: first number to be exponantiated
+    :param2: second number to be exponantiated
+    :param3: power of the first number
+    :param4: power of the second number
+    :param5: divisor of sum of exponantiated numbers
+
+    :return: division the sum of exponantiated numbers
+    """
+    return (x**a + y**b) / c
+
+call_counter = 0
+caller_dict = {}
+def fn_w_counter() -> (int, dict[str, int]):
+    caller = __name__
+    global call_counter
+    call_counter += 1
+    if caller in caller_dict:
+        caller_dict[caller] += 1
+    else:
+        caller_dict[caller] = 1
+    return call_counter, caller_dict