input: Write a function to check if any two numbers in a given list add up to a specified target number. The function should return True if there are any two numbers in the list that add up to the target, otherwise return False.
  
  def two_sum(numbers, target):
      for i in range(len(numbers)):
          for j in range(i+1, len(numbers)):
              if numbers[i] + numbers[j] == target:
                  return True
      return False
  
  assert two_sum([1, 2, 3, 4], 5)==True
  assert two_sum([1, 2, 3, 4], 8)==False
  assert two_sum([1, 2, 3, 4], 7)==True
  assert two_sum([1, 2, 3, 4], 2)==True
  assert two_sum([], 5)==False
output: def two_sum(numbers, target):
      for i in range(len(numbers)):
          for j in range(i+1, len(numbers)):
              if numbers[i] + numbers[j] == target:
                  return True
      return False