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.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String mymy = s.next();
        String first = mymy.substring(0, 2);
        String second = mymy.substring(2, 4);
        int fi = Integer.parseInt(first);
        int se = Integer.parseInt(second);
        String alg;
        if ((0 < fi && fi <= 12) && (0 < se && se <= 12)) {
            alg = "AMBIGUOUS";
        } else if (fi > 12 && se > 12) {
            alg = "NA";
        } else if (fi <= 0 || se <= 0) {
            alg = "NA";
        } else if (fi <= 12) {
            alg = "MMYY";
        } else {
            alg = "YYMM";
        }

        System.out.println(alg);
    }
}