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 sc = new Scanner(System.in);	
		
		String str = sc.next();
		
		String[] strs = str.split("");
		
		StringBuffer sbfirst = new StringBuffer();
		StringBuffer sbend = new StringBuffer();
		
		for(int i=0; i<2; i++) {
			sbfirst.append(strs[i]);
		}
		for(int i=2; i<4; i++) {
			sbend.append(strs[i]);
		}
		int firstint = Integer.parseInt(sbfirst.toString());
		int endint = Integer.parseInt(sbend.toString());
		
		if(firstint<=12 && endint<=12 && firstint != 0 && endint != 0) {
			System.out.println("AMBIGUOUS");
		}else if(firstint > 12 && endint>0 && endint <=12) {
			System.out.println("YYMM");
		}else if(endint >12 && firstint<=12 && firstint != 0) {
			System.out.println("MMYY");
		}else if(firstint >12 && endint == 0) {
			System.out.println("NA");
		}else if(endint >12 && firstint == 00) {
			System.out.println("NA");
		}else if(firstint <=12 && firstint !=0 && endint == 0) {
			System.out.println("MMYY");
		}else if(endint <= 12 && endint != 0 && firstint == 0) {
			System.out.println("YYMM");
		}else if(endint ==0 && firstint ==0) {
			System.out.println("NA");
		}
	}
}