input: Write a function to compute the sum of the values of a given dictionary. The function should iterate through the dictionary items, accumulate the sum of the values, and return the total sum. If the dictionary is empty, the function should return 0.
  
  assert dict_sum({'A':5, 'B':6, 'C':10})==21
  assert dict_sum({})==0
output: def dict_sum(d):
      return sum(d.values())