input: Write a function to find the minimum value in a list.
  assert find_min([3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]) == 1
  assert find_min([-7, -5, -6, -1, -8, -3, -4, -2, -9]) == -9
  assert find_min([42, 35, 17, 23, 50, 19]) == 17
output: def find_min(lst):
      return min(lst)