J. Jumbled String - 2019 XCPC Newbie Selection #2 (Nordic Collegiate Programming Contest 2018) - ECNU Online Judge

你可以在这里下载。

单点时限: 1.0 sec

内存限制: 512 MB

样例

Input

3 4 2 1

Output

Input

5 0 0 5

Output

impossible

NaN

A. Altruistic Amphibians B. Baby Bites C. Code Cleanups D. Delivery Delays E. Explosion Exploit F. Firing the Phaser G. Game Scheduling H. House Lawn I. Intergalactic Bidding J. Jumbled String K. King’s Colors