input: Write a function to calculate the sum of all values in a given dictionary where the keys are strings and the values are integers. If the given dictionary is empty then return 0.
  assert compute_dict_sum({"a": 5, "b": 10, "c": 15})==30
  assert compute_dict_sum({})==0
  assert compute_dict_sum({"x": 2, "y": 4})==6
  assert compute_dict_sum({"p": 1, "q": 2, "r": 3})==6
  assert compute_dict_sum({"A": 100, "B": 200})==300
output: def compute_dict_sum(d):
      return sum(d.values())