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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;

class abc126_B
{
    static void Main(string[] args)
    {
        var QS = Console.ReadLine();
        try{
            var first = int.Parse(QS.Substring(0, 2));
            var second = int.Parse(QS.Substring(2, 2));

            var firstCanMonth = 1 <= first && first <= 12;
            var secondCanMonth = 1 <= second && second <= 12;

            if(firstCanMonth && secondCanMonth) {
                Console.WriteLine("AMBIGUOUS");
            } else if(firstCanMonth) {
                Console.WriteLine("MMYY");
            } else if(secondCanMonth) {
                Console.WriteLine("YYMM");
            } else {
                Console.WriteLine("NA");
            }
        }catch(Exception) {
            Console.WriteLine("NA");
        }


    }

    
    static long[][] readLongsN(int N) { return Enumerable.Range(0, N).Select(x => readLongs()).ToArray(); }
    
    static long readLong() { return long.Parse(Console.ReadLine()); }

    static long[] readLongs() { return Console.ReadLine().Split(' ').Select(s => long.Parse(s)).ToArray(); }

}