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: Wrong Answer)

#include <stdio.h>
#include <math.h>
int main (void){
  int a[256];
  int i=0;
  int j=0;
  int mozi=0; //文字数                                                          
  char str[256];
  scanf("%[^\n]",str);
  while(1){
    if(str[i]==' '||str[i]=='\n'||str[i]=='\0'){
      a[mozi]=0;
      while(j!=0){
        a[mozi]+=(str[i-j]-'0')*pow(10,j-1);
        j--;
      }
      printf("%d\n",a[mozi]);
      mozi++;
      j=-1;
      if(str[i]=='\n'||str[i]=='\0')break;
    }
    i++;
    j++;
  }
  if(a[0]==a[1]){
   printf("%d",a[0]);
  }else{
    if(a[0]==a[2]){
      printf("%d",a[0]);
    }else{
      printf("%d",a[1]);
    }
  }
}