Problem1206--Find the Lost Sock

1206: Find the Lost Sock

[Creator : ]
Time Limit : 1 sec  Memory Limit : 128 MB

Description

Alice bought a lot of pairs of socks yesterday. But when she went home, she found that she has lost one of them. Each sock has a name which contains exactly 7 charaters.

Alice wants to know which sock she has lost. Maybe you can help her.

Input

There are multiple cases. The first line containing an integer n (1 <= n <= 1000000) indicates that Alice bought n pairs of socks. For the following 2*n-1 lines, each line is a string with 7 charaters indicating the name of the socks that Alice took back.

Output

The name of the lost sock.

Sample Input Copy

2
aabcdef
bzyxwvu
bzyxwvu
4
aqwerty
easafgh
aqwerty
easdfgh
easdfgh
aqwerty
aqwerty
2
0x0abcd
0ABCDEF
0x0abcd

Sample Output Copy

aabcdef
easafgh
0ABCDEF

Source/Category

 字符串