input: Write a python function to find a pair of numbers in a list that add up to a given target.
  assert find_pair([1, 4, 8, 10], 14) == (4, 10)
  assert find_pair([3, 2, 5, 7], 9) == (2, 7)
  assert find_pair([1, 2, 3, 4, 5], 8) == (3, 5)
output: def find_pair(numbers, target):
      seen = {}
      for number in numbers:
          complement = target - number
          if complement in seen:
              return (complement, number)
          seen[number] = True