input: Write a function to calculate the sum of two numbers, and if they are equal, return three times their sum.
  assert calculate_sum(2, 2) == 12
  assert calculate_sum(3, 3) == 18
  assert calculate_sum(2, 3) == 5
output: def calculate_sum(a, b):
      total = a + b
      if a == b:
          return 3 * total
      return total