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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Washoum
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        inputClass in = new inputClass(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        BYYMMOrMMYY solver = new BYYMMOrMMYY();
        solver.solve(1, in, out);
        out.close();
    }

    static class BYYMMOrMMYY {
        public void solve(int testNumber, inputClass sc, PrintWriter out) {
            String s = sc.nextLine();
            int first = Integer.parseInt(s.substring(0, 2));
            int second = Integer.parseInt(s.substring(2));
            if (first == 0 && second == 0) {
                out.println("NA");
            } else if (first == 0 && second <= 12) {
                out.println("YYMM");
            } else if (first == 0 && second > 12) {
                out.println("NA");
            } else if (first <= 12) {
                if (second > 12) {
                    out.println("MMYY");
                } else {
                    out.println("AMBIGUOUS");
                }
            } else {
                if (second == 0) {
                    out.println("NA");
                } else if (second <= 12) {
                    out.println("YYMM");
                } else {
                    out.println("NA");
                }
            }
        }

    }

    static class inputClass {
        BufferedReader br;

        public inputClass(InputStream in) {

            br = new BufferedReader(new InputStreamReader(in));
        }

        public String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    }
}