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 JavaScript (node.js v5.12) (judge verdict: Accepted)

process.stdin.resume();
process.stdin.setEncoding('utf8');
var input_string = '';

process.stdin.on('data', function (chunk) {
    input_string += chunk;
});
const space_input = function (line) {
    var arr = line.replace(/(^\s+)|(\s+$)/g, "").split(" ");
    for (var i = 0; i < arr.length; ++i) {
        arr[i] = +arr[i];
    }
    return arr;
};
const space_input_char = function (line) {
    var arr = line.replace(/(^\s+)|(\s+$)/g, "").split(" ");
    for (var i = 0; i < arr.length; ++i) {
        arr[i] = arr[i];
    }
    return arr;
};

process.stdin.on('end', function () {
    const lines = input_string.split('\n');
    const abc = space_input(lines[0]);
    if(abc[0]==abc[2]){
        console.log(abc[1])
    }
    if(abc[0]==abc[1]){
        console.log(abc[2])
    }
    if(abc[1]==abc[2]){
        console.log(abc[0])
    }
    
});