input: Write a function to find the GCD (Greatest Common Divisor) of two numbers using the Euclidean algorithm. The function should return the GCD of the two input numbers.
  
  assert findGCD(1000, 500) == 500
  assert findGCD(56, 98) == 14
  assert findGCD(0, 50) == 50
  assert findGCD(7, 13) == 1
  assert findGCD(120, 48) == 24
output: def findGCD(a, b):
      while b:
          a, b = b, a % b
      return a