Description

Speeding Air-Line (SAL) has multiple air-routes available, each is a one-way flight from city ~C_{from}~ to ~C_{to}~.

Now SAL launched a new offer, selling ~N~ tickets in one, leaving from ~C_a~, travel through multiple cities, and finally stay at ~C_b~.

Given the ~(C_{from}, C_{to})~ of these ~N~ air-routes, find which city is the end of the trip (~C_b~)

Limits

• number of air-routes: ~1 \le N \le 10^6~
• leaving and staying: ~C_a \ne C_b~
• take-off and landing: ~C_{from} \ne C_{to}~
• city visits count: \(Visit(\space C_a \space) = Visit(\space C_b \space) = 1\)

Input

First line contains a positive interger ~N~, following by the ~(C_{from}, C_{to})~ of these ~N~ air-routes.

Each air-routes is given by 2 lines of input:

1. the first line is ~C_{from}~, representing take-off city.
2. the second line is ~C_{to}~, representing landing city.

Sample IO

Example 1

Input

3
London
New York
New York
Lima
Lima
Sao Paulo

Output

Sao Paulo

Example 2

Input

11
Berlin
Rio de Janeiro
Sydney
Rome
New York
Tokyo
Beijing
Berlin
Moscow
Los Angeles
Tokyo
Paris
Rome
Beijing
Paris
London
Cairo
Moscow
London
Sydney
Rio de Janeiro
Cairo

Output

Los Angeles