diff --git a/Week04/functions_roca_ozdaman.py b/Week04/functions_roca_ozdaman.py
new file mode 100644
index 00000000..59d19537
--- /dev/null
+++ b/Week04/functions_roca_ozdaman.py
@@ -0,0 +1,26 @@
+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:
+    """
+    Calculates a custom equation.
+
+    :param x: Positional-only integer.
+    :param y: Positional-only integer.
+    :param a: Exponent for x.
+    :param b: Exponent for y.
+    :param c: Divisor.
+    :return: Result of (x**a + y**b) / c
+    """
+    return (x ** a + y ** b) / c
+
+def fn_w_counter() -> (int, dict[str, int]):
+    if not hasattr(fn_w_counter,'_call_counter'):
+        fn_w_counter._call_counter = 0
+        fn_w_counter._caller_dict = {}
+    caller = __name__
+    fn_w_counter._call_counter += 1
+    if caller in fn_w_counter._caller_dict:
+        fn_w_counter._caller_dict[caller] += 1
+    else:
+        fn_w_counter._caller_dict[caller] = 1
+    return fn_w_counter._call_counter,fn_w_counter._caller_dict