Matching Socks

Time limit0.5sMemory limit1024 MB

Summary

Given five digits where two pairs can be formed, print the single digit that has no matching partner.

Level: Easy1 of 10
Topics: Hash map
Solved: No attempts yet

Problem

There are $5$ socks. Each sock has one number written on it. When two socks with the same number are put together, they form a pair.

What number is written on the sock that remains after removing two pairs of socks that can be made into pairs?

Input

Five numbers, one for each sock, are given one per line. Every number in the input is between $0$ and $9$ , inclusive. The input always allows two pairs of socks to be formed.

Output

On the first line, print the number written on the remaining sock.

Examples2

Example 1
Input
```
6
8
6
3
8
```
Expected output
```
3
```
Example 2
Input
```
9
9
9
0
0
```
Expected output
```
9
```