input: from typing import List
  
  def findGCD(numbers: List[int]) -> int:
      """ Find the greatest common divisor (GCD) of two numbers.
      >>> findGCD([1000, 500])
      500
      >>> findGCD([25, 10])
      5
      """
      def gcd(a, b):
          if b == 0:
              return a
          return gcd(b, a % b)
      
      return gcd(numbers[0], numbers[1])
output:     if len(numbers) > 2:
          current_gcd = gcd(numbers[0], numbers[1])
          for num in numbers[2:]:
              current_gcd = gcd(current_gcd, num)
          return current_gcd