input: Write a function to calculate the total sum of all elements in the given list.
  
  assert calculate_sum([1, 9, 3, 5])==18
  assert calculate_sum([0, 0, 0])==0
  assert calculate_sum([-1, -2, -3])==-6
  assert calculate_sum([])==0
output: def calculate_sum(lst):
      return sum(lst)