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 <iostream>
#include <fstream>
#include <string> 
#include <cmath>  
#include <cstdlib>
#include <ctime>
#include <vector>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <functional>

using namespace std;
using ll = long long;

#define FOR(i, m, n) for(int i = (m);i < (n);i++)
#define REP(i,n) for(int i = 0; i < int(n); i++)
#define VI vector<int>
#define VVI vector<vector<int>>
#define VVVI vector<vector<vector<int>>>
#define VL vector<ll>
#define PAIR pair<int,int>
#define MP make_pair
#define VP vector<pair<int,int>>
#define VS vector<string>
#define PQUE priority_queue<int> //5,5,4,3,3,2,...
#define REPQUE priority_queue<int, vector<int>, greater<int>> //1,1,2,3,4,4,5,...
#define SUM(obj) accumulate((obj).begin(), (obj).end(), 0)
#define SORT(obj) sort((obj).begin(), (obj).end()) // 1,2,3,4,5...
#define RESORT(obj) sort((obj).begin(), (obj).end(), greater<int>()) // 5,4,3,2,1...
#define UB(obj,n) upper_bound((obj).begin(), (obj).end(), n) //itr > n
#define LB(obj,n) lower_bound((obj).begin(), (obj).end(), n) //itr>= n

const ll MOD = (ll)1e9 + 7;


int main() {
	int A, B, C;
	cin >> A >> B >> C;
	if (A == B) cout << C << endl;
	if (A == C) cout << B << endl;
	if (C == B) cout << A << endl;
	
	return 0;
}