input: Write a function to search for an element in a list and return its index.
  assert search([15, 20, 25, 30, 35], 25) == 2
  assert search([15, 20, 25, 30, 35], 40) == -1
  assert search([5, 10, 15, 20], 10) == 1
output: def search(lst, target):
      try:
          return lst.index(target)
      except ValueError:
          return -1