diff --git a/Week04/funtions_busra_pehlivanlar.py b/Week04/funtions_busra_pehlivanlar.py
new file mode 100644
index 00000000..96e89551
--- /dev/null
+++ b/Week04/funtions_busra_pehlivanlar.py
@@ -0,0 +1,21 @@
+import sys
+
+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:
+    return float((x**a + y**b) / c)
+
+def fn_w_counter():
+    if not hasattr(fn_w_counter, "calls"):
+        fn_w_counter.calls = 0
+        fn_w_counter.callers = {}
+    
+    try:
+        caller_name = sys._getframe(1).f_globals.get('__name__', '__main__')
+    except:
+        caller_name = "__main__"
+        
+    fn_w_counter.calls += 1
+    fn_w_counter.callers[caller_name] = fn_w_counter.callers.get(caller_name, 0) + 1
+    
+    return (fn_w_counter.calls, fn_w_counter.callers)