def fibo(n):
   if n == 0:
      return 0
   elif n == 1:
      return 1
   else:
      return fibo(n-1) + fibo(n-2)

#----------------------------------------------------------------------
# Main program
n = int(raw_input("Enter a nonnegative integer\n   "))
f = fibo(n)
print "Fibonacci number", n ,"=", f