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;
class Program
    {
        static void Main(string[] args)
        {
            //数の導入
            string str = Console.ReadLine();
            int[] test = new int[2];

            //二つに分離する
            for (int i = 0; i < str.Length - 1; i += 2)
            {
                test[i / 2] = int.Parse(str.Substring(i, 2));
            }

            //判定を行う
            int judge1 = 0;
            int judge2 = 0;
            //条件1を満たすか
            if (1 <= test[0] && test[0] <= 12)
                judge1 = 1;

            //条件2を満たすか
            if (1 <= test[1] && test[1] <= 12)
                judge2 = 1;

            //条件分離
            if (judge1 == 1 && judge2 == 1)
                Console.WriteLine("AMBIGUOUS");
            else if (judge1 == 1 && judge2 == 0)
                Console.WriteLine("MMYY");
            else if (judge1 == 0 && judge2 == 1)
                Console.WriteLine("YYMM");
            else
                Console.WriteLine("NA");

        }
    }