diff --git a/py/fibonacci.py b/py/fibonacci.py
index a1a519c..402571a 100644
--- a/py/fibonacci.py
+++ b/py/fibonacci.py
@@ -1,7 +1,10 @@
 #function to fibonacci sequence
 
 def fibonacci(n):
-   if n < 1:
+   #if n is lessthan 0 it return -1
+   if n == 1 and n == 0 :
        return n
+   elseif n < 0:
+       return -1
    else:
         return(fibonacci(n-1) + fibonacci(n-2))