diff --git a/41 Fibonacci Sequence.txt b/41 Fibonacci Sequence.txt
index 828b09c..219bab2 100644
--- a/41 Fibonacci Sequence.txt	
+++ b/41 Fibonacci Sequence.txt	
@@ -5,8 +5,14 @@ def fib(n):
 
     a = 0
     b = 1
-
-    if n == 1:
+    
+    if n < 0:
+      print("incorrect input")
+      
+    elif n == 0:
+      return 0
+      
+    elif n == 1:
         print(a)
 
     else:
@@ -17,6 +23,6 @@ def fib(n):
         c = a + b
         a = b
         b = c
-        print(a+b)
+        print(c)
 
-fib(100)
+fib(9)