input: Write a python function to search for an element in an array and return its index. Return -1 if the element is not found.
  assert search([10, 8, 5, 15], 15) == 3
  assert search([10, 8, 5, 15], 8) == 1
  assert search([10, 8, 5, 15], 5) == 2
  assert search([10, 8, 5, 15], 7) == -1
output: def search(arr, target):
      try:
          return arr.index(target)
      except ValueError:
          return -1