input: Write a function to compute the sum of two variables and store the result in a third variable. Then print the result. 
  
  assert compute_sum(5, 8) == 13
  assert compute_sum(10, 20) == 30
  assert compute_sum(-5, 5) == 0
  assert compute_sum(3, 7) == 10
output: def compute_sum(a, b):
      result = a + b
      return result