input: Write a function to find the closest number to a target in a list of numbers.
  assert find_closest([2, 4, 7, 8], 5) == 4
  assert find_closest([1, 3, 5, 6], 4) == 3
  assert find_closest([-2, -5, -1], -3) == -2
  assert find_closest([10, 20, 30], 25) == 20
output: def find_closest(numbers, target):
      return min(numbers, key=lambda x: abs(x - target))