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: Runtime Error)

using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static void Main(string[] args)
    {
        string[] s = Console.ReadLine().Split(' ');
        int H = int.Parse(s[0]);
        int W = int.Parse(s[1]);
        string[] map = new string[H + 2];
        for(int i = 0; i < W+ 2; i++)
        {
            map[0] += ".";
            map[H + 1] += ".";
        }
        for (int i = 1; i <= H; i++)
            map[i] = "." + Console.ReadLine() + ".";

        for (int y = 1; y <= H; y++)
        {
            for (int x = 1; x <= W; x++)
            {
                if (map[y][x] == '#')
                    Console.Write('#');
                else
                {
                    int sum = 0;
                    if (map[y - 1][x - 1] == '#') sum++;
                    if (map[y - 1][x] == '#') sum++;
                    if (map[y - 1][x + 1] == '#') sum++;
                    if (map[y][x + 1] == '#') sum++;
                    if (map[y + 1][x + 1] == '#') sum++;
                    if (map[y + 1][x] == '#') sum++;
                    if (map[y + 1][x - 1] == '#') sum++;
                    if (map[y][x - 1] == '#') sum++;
                    Console.Write(sum);
                }
            }
            Console.WriteLine();
        }
    }
}