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: Wrong Answer)

using System;
using System.Text;


namespace ABC126
{
    class Program
    {
        static int Main(string[] args)
        {
            ProblemB();
            return 0;
        }

        static void ProblemB()
        {
            int input = int.Parse(System.Console.ReadLine());
            string answer;

            int ba, dc;
            ba = input % 100;
            dc = (input - ba)/100;

            //YYMM
            if(ba <= 12)
            {
                if(dc <= 12)
                {
                    answer = "AMBIGUOUS";
                }
                else
                {
                    answer = "YYMM";
                }

            }
            //notYYMM
            else
            {
                if(dc <=12)
                {
                    answer = "MMYY";
                }
                else
                {
                    answer = "NA";
                }
            }

            Console.WriteLine(answer);
        }

        static int ProblemA()
        {
            string[] K = System.Console.ReadLine().Split(' ');
            string S = System.Console.ReadLine();
            string L = S.ToLower();
            char[] Answer = new char[S.Length];

            for(int i = 0; i < S.Length; i++)
            {
                if(i == int.Parse(K[1])-1)
                {
                    Answer[i] = L[i];
                }
                else
                {
                    Answer[i] = S[i];
                }
            }

            Console.WriteLine(Answer);

            return 0;
        }
    }


}