Problem:
Score : 100 points

Problem Statement

You are given three integers, A, B and C.

Among them, two are the same, but the remaining one is different from the rest.

For example, when A=5,B=7,C=5, A and C are the same, but B is different.

Find the one that is different from the rest among the given three integers.

Constraints

-100 \leq A,B,C \leq 100

A, B and C are integers.

The input satisfies the condition in the statement.

Input

Input is given from Standard Input in the following format:

A B C

Output

Among A, B and C, print the integer that is different from the rest.

Sample Input 1

5 7 5

Sample Output 1

7

This is the same case as the one in the statement.

Sample Input 2

1 1 7

Sample Output 2

7

In this case, C is the one we seek.

Sample Input 3

-100 100 100

Sample Output 3

-100

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

namespace ABC
{
    class ABC075A
    {
        static void Main(string[] args)
        {
            string[] str = Console.ReadLine().Split(' ');
            int a = int.Parse(str[0]);
            int b = int.Parse(str[1]);
            int c = int.Parse(str[2]);

            int ans = 0;
            if(a == b) { ans = c; }
            else if (a == c) { ans = b; }
            else if (b == c) { ans = a; }

            Console.WriteLine("{0}", ans);
        }
    }
}