input: Write a python function to find the minimum value in a list.
  assert find_min([4, 2, 9, 11, 5, 1]) == 1
  assert find_min([15, 22, 3, 7, 14]) == 3
  assert find_min([100, 200, 300, 50, 400]) == 50
output: def find_min(lst):
      return min(lst)