input: Write a function to perform binary search on a sorted list and return the index of the item if found, otherwise return -1.
  assert binary_search(3, [1, 2, 3, 4, 5]) == 2
  assert binary_search(10, [1, 3, 5, 7, 9]) == -1
  assert binary_search(4, [2, 4, 6, 8, 10]) == 1
  assert binary_search(8, [1, 2, 3, 4, 5, 6, 7, 8, 9]) == 7
output: def binary_search(item, lst):
      left, right = 0, len(lst) - 1
      while left <= right:
          mid = (left + right) // 2
          if lst[mid] == item:
              return mid
          elif lst[mid] < item:
              left = mid + 1
          else:
              right = mid - 1
      return -1