input: Write a python function to get the index of an item in a list.
  assert getIndex([1, 2, 3, 4, 5, 6], 5) == 4
  assert getIndex([10, 20, 30, 40, 50], 30) == 2
  assert getIndex([7, 14, 21, 28], 14) == 1
  assert getIndex([7, 14, 21, 28], 100) == -1
output: def getIndex(lst, item):
      try:
          return lst.index(item)
      except ValueError:
          return -1