
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	}

} Main public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	} main {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.nextLine(); S sc.nextLine() sc.nextLine sc String YY = S.substring(0, 2); YY S.substring(0, 2) S.substring S 0 2 String MM = S.substring(2, 4); MM S.substring(2, 4) S.substring S 2 4 int yy = Integer.parseInt(YY); yy Integer.parseInt(YY) Integer.parseInt Integer YY int mm = Integer.parseInt(MM); mm Integer.parseInt(MM) Integer.parseInt Integer MM if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		} (yy > 12  || yy == 0)&& (1 <= mm && mm <=12) (yy > 12  || yy == 0) yy > 12 yy 12 yy == 0 yy 0 (1 <= mm && mm <=12) 1 <= mm 1 mm mm <=12 mm 12 {//
			System.out.println("YYMM");
		} System.out.println("YYMM") System.out.println System.out System System.out "YYMM" if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		} (12 >= yy && yy > 0) && (mm > 12 || mm == 0) (12 >= yy && yy > 0) 12 >= yy 12 yy yy > 0 yy 0 (mm > 12 || mm == 0) mm > 12 mm 12 mm == 0 mm 0 {//0100
			System.out.println("MMYY");
		} System.out.println("MMYY") System.out.println System.out System System.out "MMYY" if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		} 12 >= yy && (1 <= mm && mm <=12) 12 >= yy 12 yy (1 <= mm && mm <=12) 1 <= mm 1 mm mm <=12 mm 12 {
			System.out.println("AMBIGUOUS");
		} System.out.println("AMBIGUOUS") System.out.println System.out System System.out "AMBIGUOUS" {
			System.out.println("NA");
		} System.out.println("NA") System.out.println System.out System System.out "NA" String[] args args public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	}

} public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	}

} Main

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		//1234
		String YY = S.substring(0, 2);
		String MM = S.substring(2, 4);

		int yy = Integer.parseInt(YY);
		int mm = Integer.parseInt(MM);

		//YYMM
		//yy>12 && 01 <= MM <= 12

		//MMYY
		//13 > yy && MM >12

		//AMBIGUOUS
		//01 <= MM <= 12 && 12 >= yy

		//NA
		// else
		if((yy > 12  || yy == 0)&& (1 <= mm && mm <=12)){//
			System.out.println("YYMM");
		}else if((12 >= yy && yy > 0) && (mm > 12 || mm == 0)) {//0100
			System.out.println("MMYY");
		}else if(12 >= yy && (1 <= mm && mm <=12) ) {
			System.out.println("AMBIGUOUS");
		}else {
			System.out.println("NA");
		}


	}

}
