From 84e9b8a8c96654aef693c03b035a8908f8ec0b91 Mon Sep 17 00:00:00 2001
From: MelodyZhangYiqun <yiqunz@andrew.cmu.edu>
Date: Wed, 31 Aug 2022 12:59:43 -0400
Subject: [PATCH] negative issue resolved

---
 fib.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fib.py b/fib.py
index 421cfab..7a0ab37 100644
--- a/fib.py
+++ b/fib.py
@@ -6,6 +6,8 @@
 Negative numbers should return None
 """
 def fibonacci(position):
+  if(position<0):
+    return None
   if(position == 1 or position == 2):
     return 1
   return fibonacci(position - 1) + fibonacci(position - 2)