Score : $100$ points
Takahashi threw three dice, and they showed three numbers $a$, $b$, and $c$.
If there are two same numbers among $a$, $b$, and $c$, print the remaining number. Otherwise, print $0$.
Input is given from Standard Input in the following format:
$a$ $b$ $c$
If there are two same numbers among $a$, $b$, and $c$, print the remaining number. Otherwise, print $0$.
2 5 2
5
The first and third dice both showed $2$, so we should print the number on the remaining dice, which is $5$.
4 5 6
0
Any two numbers are different, so we should print $0$.
1 1 1
1
Any two numbers are the same. Whichever two dice we choose, the number on the remaining dice will be $1$.