input: Write a function to find the Greatest Common Divisor (GCD) of two numbers using the Euclidean algorithm. The function should take two integers as input and return the GCD of the two numbers. If one of the numbers is zero, the function should return the non-zero number as the GCD.
  assert findGCD(1000, 500)==500
  assert findGCD(56, 98)==14
  assert findGCD(10, 0)==10
  assert findGCD(0, 7)==7
  assert findGCD(15, 30)==15
output: def findGCD(a, b):
      while b != 0:
          a, b = b, a % b
      return a