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: Runtime Error)

#include "stdio.h"

int main()
{
  int A, B, C;
  scanf("%3i %3i %3i%[^\n]", &A, &B, &C);
  getchar();
  if (A == B) printf("%i\n", C);
  if (A == C) printf("%i\n", B);
  if (B == C) printf("%i\n", A);
  return 0;
}