P9855 [CCC 2008 J2] Do the Shuffle

Those tiny music machines that play your digital music are really computers that keep track of and play music files. The CCC music player $(C^3MP)$ is currently in development and will be hitting the stores soon! In this problem, you have to simulate a $C^3MP$. The $C^3MP$ music player will hold $5$ songs in memory, whose titles will always be `A`, `B`, `C`, `D`, `E`. The $C^3MP$ also keeps track of a playlist, which is an ordering of all the songs. The $C^3MP$ has 4 buttons that the user will press to rearrange the playlist and play the songs. Initially, the $C^3MP$ playist 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, $1 \leq b \leq 4$, and n represents the number of times that the user wants to press button b. You can assume that n always satisfies $1 \leq n \leq 10$.

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.