input: Write a function to compute the sum of all values in a dictionary (string → integer) and return the result. If the dictionary is empty, return 0.
  
  assert compute_dict_sum({"a": 5, "b": 10, "c": 15}) == 30
  assert compute_dict_sum({"x": 1, "y": 2, "z": 3}) == 6
  assert compute_dict_sum({}) == 0
  assert compute_dict_sum({"p": 100}) == 100
  assert compute_dict_sum({"q": -5, "r": 5}) == 0
output: def compute_dict_sum(d):
      return sum(d.values()) if d else 0