diff --git a/Week04/functions_zeynepsude_bayram.py b/Week04/functions_zeynepsude_bayram.py
new file mode 100644
index 00000000..674dde48
--- /dev/null
+++ b/Week04/functions_zeynepsude_bayram.py
@@ -0,0 +1,25 @@
+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 (x**a + y**b) / c.
+
+    :param x: First base
+    :param y: Second base
+    :param a: Exponent of x
+    :param b: Exponent of y
+    :param c: Divisor
+    :return: (x**a + y**b) / c
+    """
+    if not all(isinstance(i, int) for i in (x, y, a, b, c)):
+        raise TypeError("All parameters must be integers")
+    return (x ** a + y ** b) / c
+
+
+counter = {}
+
+
+def fn_w_counter() -> (int, dict[str, int]):
+    counter[__name__] = counter.get(__name__, 0) + 1
+    return sum(counter.values()), counter