P21383 [AtCoder] You have a digit sequence S of length 4. You are wondering which of the following formats S is in:
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题目描述

You have a digit sequence S of length 4. You are wondering which of the following formats S is in:
- YYMM format: the last two digits of the year and the two-digit representation of the month (example: 01 for January), concatenated in this order
- MMYY format: the two-digit representation of the month and the last two digits of the year, concatenated in this order
If S is valid in only YYMM format, print YYMM; if S is valid in only MMYY format, print MMYY; if S is valid in both formats, print AMBIGUOUS; if S is valid in neither format, print NA.

-----Constraints-----
- S is a digit sequence of length 4.

-----Input-----
Input is given from Standard Input in the following format:
S

-----Output-----
Print the specified string: YYMM, MMYY, AMBIGUOUS or NA.

-----Sample Input-----
1905

-----Sample Output-----
YYMM

May XX19 is a valid date, but 19 is not valid as a month. Thus, this string is only valid in YYMM format.

输入格式

见题面

输出格式

见题面

样例输入
1905
样例输出
YYMM