input: Write a function to multiply all integers between two given numbers (inclusive).
  assert multiply_between(2, 10) == 3628800
  assert multiply_between(1, 5) == 120
  assert multiply_between(3, 3) == 3
output: def multiply_between(a, b):
      result = 1
      for i in range(a, b + 1):
          result *= i
      return result