input: 
  def findGCD(a, b):
      """
      Write a Python script to find the GCD of two numbers.
      Example:
      >>> findGCD(1000, 500)
      500
      """
      if b == 0:
          return a
      return findGCD(b, a % b)
  
output:     if b == 0:
          return a
      return findGCD(b, a % b)