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: Accepted)

import java.util.*;
import java.text.*;
public class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
       String a = sc.next();
        DateFormat df1 = new SimpleDateFormat("MMyy");
        DateFormat df2 = new SimpleDateFormat("yyMM");
        df1.setLenient(false);
        df2.setLenient(false);
        String s="";
        try{
            df1.parse(a);
            s="MMYY";
            df2.parse(a);
            s="AMBIGUOUS";
        } catch (ParseException e) {
            try{
                df2.parse(a);
                s="YYMM";
            }catch (Exception f){

            }
        }
        if(s.equals("")){
            s="NA";
        }
        System.out.println(s);

    }
}