input: Write a function to compute the sum of two given integers and store the result in a third variable. Return the third variable which will hold the sum of the two integers.
  def sum_two_numbers(x, y):
      result = x + y
      return result
  assert sum_two_numbers(5, 8)==13
  assert sum_two_numbers(-3, 10)==7
  assert sum_two_numbers(0, 0)==0
  assert sum_two_numbers(7, -7)==0
output: def sum_two_numbers(x, y):
      result = x + y
      return result