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 <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 

using namespace std;

int main() {
	map<int, int>mp;
	int num1, num2 ,num3;

	cin >> num1;
	mp[num1]++;
	cin >> num2;
	mp[num2]++;

	cin >> num3;
	mp[num3]++;

	if (mp[num1] == 1) {
		cout << num1 << endl;
	}else if (mp[num2] == 1) {
		cout << num2 << endl;
	}else if (mp[num3] == 1) {
		cout << num3 << endl;
	}





	return 0;
}