T569671 【FUN】Math Problems

Due to taking a break from regular classes to focus on learning OI, Sky's performance in cultural subjects started to decline. In order to catch up on the cultural subjects in time, Sky found some math problems on English websites. It was said that these problems, could improve Sky's abilities across various subjects through interdisciplinary integration. Sky was very excited and decided to configure them into an OI problem - by inputting a number representing the subproblem’s ID, one only needs to output the answer to the corresponding subproblem. Sky also set up special test cases with the rule that, regardless of which subproblems were solved, the test points marked as AC (Accepted) would always correspond to the first $k$ subproblems, where $k$ was the number of solved subproblems. However, Sky found that he accidentally confused the order of these problems, and only by correctly answering the corresponding problem when inputting the ID can one get the score for that problem. Therefore, he has to turn to you to see if someone proficient in both Chinese and English like you can help him solve the problem correctly.

The problems are as follows: 

Input a number representing the subproblem’s ID (1-index).

Output the answers to the corresponding subproblem in a correct format. For multiple-choice questions, only one uppercase letter should be output to indicate the option. For non-multiple-choice questions, the output should not contain redundant information such as English letters and special symbols other than decimal points.

Aqua: Actually, I remember Sky numbered the questions in alphabetical order at that time...