new_contents: # https://www.hackerrank.com/challenges/ctci-lonely-integer
  #!/bin/python3
  
  import sys
  
  def lonely_integer(a):
      value = 0
      for x in a:
          prev_value = value
          new_value = value ^ x
          value = new_value
      return value
  
  
  # n = int(input().strip())
  # a = [int(a_temp) for a_temp in input().strip().split(' ')]
  n = 5
  a = [0, 0, 1, 2, 1]
  print(lonely_integer(a))
  
  
  test = 3 + 12
  print(test ^ 3)
  print(test ^ 12)
  
  
subject: Implement solution to get the lone integer in an array