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.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S =sc.nextLine();
		int[] form = new int[3];
		form[0] =Integer.parseInt(S.substring(0, 2));
		form[1] =Integer.parseInt(S.substring(2, 4));
		if(form[0] > 0 && form[0] < 13){
			yearSurv(form[1]);
		}
		else if(form[0] >= 13 && form[0] < 100){
			monthSurv(form[1]);
		}
		else if(form[0] == 0){
			monthSurv(form[1]);
		}
		else{
			System.out.println("NA");
		}
	}
	
	public static void yearSurv(int year){
		if(year > 0 && year <13 ){
			System.out.println("AMBIGUOUS");
		}
		else if(year >= 13 && year <100){
			System.out.println("MMYY");
		}
		else if(year == 0){
			System.out.println("MMYY");
		}
		else{
			System.out.println("NA");
		}
	}
	
	public static void monthSurv(int month){
		if(month > 0 && month < 13){
			System.out.println("YYMM");
		}
		else{
			System.out.println("NA");
		}
	}
}