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 Python (3.4.3) (judge verdict: Runtime Error)

def count_mine(m, i, j):
    count = 0
    for k in range(i - 1, i + 2):
        for l in range(j - 1, j + 2):
            if m[k][l] == "#":
                count += 1
    return count

H, W = map(int, input().split())
l = [list(map(str, input().split())) for i in range(H)]
m = []
m.append("*" * (W + 2))
for i in range(len(l)):
    add_colum = "*" + ''.join(l[i]) + "*"
    m.append(add_colum)
m.append("*" * (W + 2))
answer = []
for i in range(1, H + 1):
    answer_column = ""
    for j in range(1, W + 1):
        if m[i][j] == ".":
            answer_column += str(count_mine(m, i, j))
        else:
            answer_column += "#"
    answer.append(answer_column)
for i in range(H):
    print(answer[i])