Canadian Computing Competition: 2008 Stage 1, Junior #2

Those tiny music machines that play your digital music are really computers that keep track of and play music files. The CCC music player (C 3 MP) is currently in development and will be hitting the stores soon! In this problem, you have to simulate a C 3 MP.

The C 3 MP music player will hold 5 songs in memory, whose titles will always be "A", "B", "C", "D" and "E". The C 3 MP also keeps track of a playlist , which is an ordering of all the songs. The C 3 MP has 4 buttons that the user will press to rearrange the playlist and play the songs.

Initially, the C 3 MP playlist is "A, B, C, D, E". The 4 control buttons do the following:

• Button 1: move the first song of the playlist to the end of the playlist. For example: "A, B, C, D, E" will change to "B, C, D, E, A".
• Button 2: move the last song of the playlist to the start of the playlist. For example, "A, B, C, D, E" will change to "E, A, B, C, D".
• Button 3: swap the first two songs of the playlist. For example, "A, B, C, D, E" will change to "B, A, C, D, E".
• Button 4: stop rearranging songs and output the playlist.

You need to write a program to simulate a CCC music player. Your program should repeatedly ask for two positive integers \(b\) and \(n\) . Here \(b\) represents the button number that the user wants to press, \(1 \le b \le 4\) , and \(n\) represents the number of times that the user wants to press button \(b\) . You can assume that \(n\) always satisfies \(1 \le n \le 10\) .

The input will always finish with the pair of inputs ( \(b = 4\) , \(n = 1\) ) when this happens, you should print the order of songs in the current playlist and your program should end. You can assume that the user will only ever press button 4 once.

Sample Input

2
1
3
1
2
3
4
1

Output for Sample Input

B C D A E

Explanation

• (initial playlist is "A, B, C, D, E")
• ( \(b = 2\) , \(n = 1\) so "A, B, C, D, E" changed to "E, A, B, C, D")
• ( \(b = 3\) , \(n = 1\) , so "E, A, B, C, D" changed to "A, E, B, C, D")
• ( \(b = 2\) , \(n = 3\) , so "A, E, B, C, D" changed to "B, C, D, A, E")
• ( \(b = 4\) , \(n = 1\) ) When this happens, you should output the playlist.