input: Write a function to get the maximum value from a dictionary.
  assert get_max_value({'a': 10, 'b': 20, 'c': 30}) == 30
  assert get_max_value({'x': 5, 'y': 3, 'z': 15}) == 15
  assert get_max_value({'alpha': 100, 'beta': 200, 'gamma': 150}) == 200
output: def get_max_value(d):
      return max(d.values())