Problem:
Score : 200 points

Problem Statement

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 1

1905

Sample Output 1

YYMM

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

Sample Input 2

0112

Sample Output 2

AMBIGUOUS

Both December XX01 and January XX12 are valid dates. Thus, this string is valid in both formats.

Sample Input 3

1700

Sample Output 3

NA

Neither 0 nor 17 is valid as a month. Thus, this string is valid in neither format.

Solution in Python (3.4.3) (judge verdict: Accepted)

def is_mm(target):
    n = int(target)
    return 1 <= n <= 12


def get_result(first2_is_mm, last2_is_mm):
    if first2_is_mm and last2_is_mm:
        return "AMBIGUOUS"
    if not first2_is_mm and not last2_is_mm:
        return "NA"
    if first2_is_mm:
        return "MMYY"
    return "YYMM"


s = str(input())
first2, last2 = ((i + j) for (i, j) in zip(s[::2], s[1::2]))
print(get_result(is_mm(first2), is_mm(last2)))