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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>

#define _CRT_SECURE_NO_WARNINGS
#define TLong long long 

// fact(n)
int fact(int n){
	if(n == 1)	return 1;
	else return (n * fact(n - 1));
}

// combination(n,r)
int combination(int n, int r){

	if(r == 0 || r == n)	return 1;
	else if(r == 1)	return n;
	return (combination(n - 1, r - 1) + combination(n - 1, r));
}

// gcd(a,b)
int gcd(int a,int b){
	int ret;
	ret = (b == 0) ? a : gcd(b, a % b);
	return ret;
}

// lcm(a.b)
int lcm(int a,int b){
	return (a * b) / gcd(a,b);
}

// qsort(array, size, sizeof(int),comp);
int comp(const int *a,const int *b){
	return (*a - *b);
}

// append(array,*size,addNum)
void append(int *array,int *size,int num){
	realloc(array, sizeof(int) * (*size + 1));
	array[(*size)] = num;
	++(*size);
}

// pop(array,*size) & nongetpop(array,*size)
int pop(int *array,int *size){
	int temp = array[(*size - 1)];
	realloc(array,sizeof(int) * (*size - 1));
	--(*size);
	return temp;
}

void nongetpop(int *array,int *size){
	realloc(array,sizeof(int) * (*size - 1));
	--(*size);
}

int main(int argc, char const *argv[]){
	int a,b,c;
	scanf("%d%d%d\n", &a,&b,&c);
	if(a == b)	printf("%d\n",c);
	else if(a == c)	printf("%d\n",b);
	else printf("%d\n",a);
	return 0;
}