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 <bits/stdc++.h>
using namespace std ;

#define DEBUG(x) cout << '>' << #x << ':' << x << endl;
#define mem(x,val) memset((x),(val),sizeof(x))
#define all(x) x.begin(),x.end()
#define pb push_back
#define mp make_pair
#define PI acos(-1.0) 
#define MAXN 11111

const int INF = 1 << 29 ;
typedef long long ll ;
typedef pair < int , int > pii ;

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 ;
}