input: Write a python function to add two numbers using LRU cache.
  assert add_two_numbers(1, 2) == 3
  assert add_two_numbers(10, 20) == 30
  assert add_two_numbers(0, 0) == 0
output: from functools import lru_cache
  
  @lru_cache(maxsize=None)
  def add_two_numbers(a, b):
      return a + b