input: Write a python function to perform a linear search on a list and return the 1-based index of the element if found, otherwise return -1.
  assert linear_search([2, 3, 4, 5], 4) == 3
  assert linear_search([1, 2, 3, 4, 5], 1) == 1
  assert linear_search([1, 2, 3, 4, 5], 6) == -1
output: def linear_search(lst, target):
      for i, element in enumerate(lst):
          if element == target:
              return i + 1
      return -1