#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Thu Jan 10 11:47:46 2019

@author: harriet
"""


#Given 3 int values, a b c, return their sum. However, if one of the values is the same as another of the values, it does not count towards the sum.
#
#
#lone_sum(1, 2, 3) → 6
#lone_sum(3, 2, 3) → 2
#lone_sum(3, 3, 3) → 0

def lone_sum(a, b, c):
  if a == b == c:
    return 0
  elif a == b:
    return c
  elif b == c:
    return a
  elif a == c:
    return b
  else:
    return a+b+c
  
    