diff --git a/Week04/functions_ayseselin_kargi.py b/Week04/functions_ayseselin_kargi.py
new file mode 100644
index 00000000..be511731
--- /dev/null
+++ b/Week04/functions_ayseselin_kargi.py
@@ -0,0 +1,33 @@
+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:
+    """
+    Computes a custom equation.
+
+    :param x: positional-only
+    :param y: positional-only
+    :param a: positional or keyword
+    :param b: positional or keyword
+    :param c: keyword-only
+    :return: result as float
+    """
+
+    for val in (x, y, a, b, c):
+        if not isinstance(val, int):
+            raise TypeError("Arguments must be integers")
+
+    return float((x ** a + y ** b) / c)
+
+
+def fn_w_counter() -> (int, dict[str, int]):
+    if not hasattr(fn_w_counter, "count"):
+        fn_w_counter.count = 0
+
+    fn_w_counter.count += 1
+
+    module_name = __name__.split('.')[-1]
+
+    return fn_w_counter.count, {module_name: fn_w_counter.count}