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;
import java.util.stream.Stream;


public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
//		int[] S = Stream.of(sc.nextLine().split("")).mapToInt(Integer::parseInt).toArray();
		String[] S = sc.nextLine().split("");
		
		int v_mae   = Integer.parseInt(S[0]+S[1]);
		int v_usiro = Integer.parseInt(S[2]+S[3]);
		boolean yymm_flg = false;
		boolean mmyy_flg = false;
		
		if(1 <= v_mae && v_mae <= 99 && 1 <= v_usiro && v_usiro <= 12 ) {
			yymm_flg=true;
		}
		if(1 <= v_usiro && v_usiro <= 99 && 1 <= v_mae && v_mae <= 12 ) {
			mmyy_flg=true;
		}
		
		if(yymm_flg && !mmyy_flg) {
			System.out.print("YYMM");
		}
		else if(!yymm_flg && mmyy_flg) {
			System.out.print("MMYY");
		}
		else if(yymm_flg && mmyy_flg) {
			System.out.print("AMBIGUOUS");
		}
		else {
			System.out.print("NA");
		}
	}
}