input: Write a function to find the GCD of two numbers using the Euclidean algorithm.
  
  def findGCD(a, b): 
     if (b == 0): 
         return a
     return findGCD(b, a % b)
  
  assert findGCD(1000, 500) == 500
  assert findGCD(8, 12) == 4
  assert findGCD(56, 98) == 14
  assert findGCD(18, 24) == 6
  assert findGCD(48, 18) == 6
output: def findGCD(a, b): 
     if (b == 0): 
         return a
     return findGCD(b, a % b)