Problem Description

Many local and international recreational runners are eager to participate in this year's Zagreb Marathon! It is a traditional race with a length of 42125 meters. An odd statistic is that this year, every participant except one managed to complete the race.

Please help the organizers determine the identity of the participant who did not complete the race based on the list of registered participants and the ranking list.

Input Format

The first line of input contains the integer $n$, which is the number of participants.

Each of the following $n$ lines contains the name of a registered participant.

The next $n-1$ lines contain the names of the participants who completed the race, listed in the order they finished. The names of the participants consist of English letters. The names of the participants are not necessarily unique.

Output Format

The first and only line of output must contain the name of the participant who did not complete the race.

Sample Input and Output

Sample Input #1

3
leo
kiki
eden
eden
kiki

Sample Output #1

leo

Sample Input #2

5
marina
josipa
nikola
vinko
filipa
josipa
filipa
marina
nikola

Sample Output #2

vinko

Sample Input #3

4
mislav
stanko
mislav
ana
stanko
ana
mislav

Sample Output #3

mislav

Notes

Data Size and Constraints

• For $50\%$ of the data, $1 \le n \le 10^3$.
• For $100\%$ of the data, $1 \le n \le 10^5$.

Let $|s|$ be the length of the participant's name. For all valid names, $1 \le |s| \le 20$, and the names consist only of lowercase characters.

Notes

This problem is translated from COCI2014-2015 CONTEST #2 T2 UTRKA.

见题面 Input 部分

见题面 Output 部分