input: def linearSearch(arr: List[int], value: int) -> int:
      """Search for a given value in an array and return the index of the value if found,
      otherwise return -1 if not found.
      >>> linearSearch([5, 3, 7, 2], 7)
      2
      >>> linearSearch([5, 3, 7, 2], 4)
      -1
      """
output:     for i in range(len(arr)):
          if arr[i] == value:
              return i
      return -1