input: Write a function to compute the sum of the values of a given dictionary. If the given dictionary is empty, return 0.
  def dict_sum(dict):
      sum = 0
      for key, value in dict.items():
          sum += value
      return sum
  
  assert dict_sum({'A':5, 'B':6, 'C':10})==21
  assert dict_sum({'A':1, 'B':2, 'C':3, 'D':4})==10
  assert dict_sum({})==0
  assert dict_sum({'X':15, 'Y':25})==40
output: def dict_sum(dict):
      sum = 0
      for key, value in dict.items():
          sum += value
      return sum