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.Scanner;
import java.util.HashMap;
import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
import java.lang.Math;

public class Main {

    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String s = sc.next();
        int fh = Integer.parseInt("" + s.charAt(0) + s.charAt(1));
        int sh = Integer.parseInt("" + s.charAt(2) + s.charAt(3));
        String ans;
        if (fh >= 0 && fh < 100 && sh > 0 && sh < 13) {
            if (sh >= 0 && sh < 100 && fh > 0 && fh < 13) {
                ans = "AMBIGUOUS";
            } else {
                ans = "YYMM";
            }
        } else if (sh >= 0 && sh < 100 && fh > 0 && fh < 13) {
            ans = "MMYY";
        } else {
            ans = "NA";
        }
        System.out.println(ans);
    }

}