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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

function Main(input) {
	s = input
    a = s.slice(0, 2) * 1 
    b = s.slice(-2) * 1
    c = d = false
    ans = ''
    if (1 <= a && a <= 12) {
      c = true
    }
    if (1 <= b && b <= 12) {
      d = true
    }
    if (c && d) {
      ans = 'AMBIGUOUS'
    } else if (c) {
      ans = 'MMYY'
    } else if (d) {
      ans = 'YYMM'
    } else {
      ans = 'NA'
    }
	console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));