ICM Technex 2017 and Codeforces Round 400 (Div. 1 + Div. 2, combined)
A
A Serial Killer
Codeforces
900
原题
←B →
翻译中…

Our beloved detective, Sherlock is currently trying to catch a serial killer who kills a person each day. Using his powers of deduction, he came to know that the killer has a strategy for selecting his next victim.

翻译中…

The killer starts with two potential victims on his first day, selects one of these two, kills selected victim and replaces him with a new person. He repeats this procedure each day. This way, each day he has two potential victims to choose from. Sherlock knows the initial two potential victims. Also, he knows the murder that happened on a particular day and the new person who replaced this victim.

翻译中…

You need to help him get all the pairs of potential victims at each day so that Sherlock can observe some pattern.

翻译中…

Input

翻译中…

First line of input contains two names (length of each of them doesn't exceed $10$), the two initials potential victims. Next line contains integer $*n*$ ($1 ≤ *n* ≤ 1000$), the number of days.

翻译中…

Next $*n*$ lines contains two names (length of each of them doesn't exceed $10$), first being the person murdered on this day and the second being the one who replaced that person.

翻译中…

The input format is consistent, that is, a person murdered is guaranteed to be from the two potential victims at that time. Also, all the names are guaranteed to be distinct and consists of lowercase English letters.

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Output

翻译中…

Output $*n* + 1$ lines, the $*i*$-th line should contain the two persons from which the killer selects for the $*i*$-th murder. The $(*n* + 1)$-th line should contain the two persons from which the next victim is selected. In each line, the two names can be printed in any order.

翻译中…

Note

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In first example, the killer starts with ross and rachel.

翻译中…
  • After day $1$, ross is killed and joey appears.
  • After day $2$, rachel is killed and phoebe appears.
  • After day $3$, phoebe is killed and monica appears.
  • After day $4$, monica is killed and chandler appears.
翻译中…

样例

Input #1
ross rachel
4
ross joey
rachel phoebe
phoebe monica
monica chandler
Output #1
ross rachel
joey rachel
joey phoebe
joey monica
joey chandler
InputCopy OutputCopy
Input #2
icm codeforces
1
codeforces technex
Output #2
icm codeforces
icm technex
InputCopy OutputCopy
题目信息
题号
776A
时间限制
2 s
内存限制
256 MB
标签
暴力
模拟
字符串

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。