input: Write a function to check if any two numbers from a given list sum up to a target number. If any pair sums up to the target, return True, otherwise return False.
  def check_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 check_sum([1, 2, 3, 4, 5], 9) == True
  assert check_sum([1, 2, 3, 4, 5], 10) == False
  assert check_sum([5, 5, 5, 5], 10) == True
  assert check_sum([1, 2, 3, 4, 5], 4) == True
  assert check_sum([1, 2, 3, 4, 5], 0) == False
output: def check_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