output_description: Output the greatest common divisor of _a_ and _b_.
input_description: _a_ and _b_ are given in a line sparated by a single space.
attempt: A = list(map(int, input().split()))
  max = 1
  for m in range(1, A[0] if A[0] < A[1] else A[1]):
      if A[0] % m == 0 and A[1] % m == 0:
          max = m
  print(max)
  
problem_description: Greatest Common Divisor
  
  Write a program which finds the greatest common divisor of two natural numbers
  _a_ and _b_
samples: [{"input": "54 20", "output": "2"}, {"input": "147 105", "output": "21"}]