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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <cstdio>
#include <iostream> 
#include <string>
#include <vector>
#include <sstream>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cstring>

using namespace std;
using ll = long long;

const ll INF = 1e9;
const ll MOD = 1e9 + 7;
int dx[4] = { 1,0,-1,0 };
int dy[4] = { 0,1,0,-1 };

int main() 
{
	int a, b, c;

	cin >> a >> b >> c;

	if (a == b) {
		cout << c << endl;
	}
	else if (b == c) {
		cout << a << endl;
	}
	else {
		cout << b << endl;
	}

	return 0;
}