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-----
5 7 5

-----Sample Output-----
7

This is the same case as the one in the statement.

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