import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

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

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

	} main {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc int a = Integer.parseInt(s.substring(0, 2)); a Integer.parseInt(s.substring(0, 2)) Integer.parseInt Integer s.substring(0, 2) s.substring s 0 2 int b = Integer.parseInt(s.substring(2, 4)); b Integer.parseInt(s.substring(2, 4)) Integer.parseInt Integer s.substring(2, 4) s.substring s 2 4 if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		} a <= 12 && a >= 1 && b <= 12 && b >= 1 b <= 12 a <= 12 && a >= 1 && b <= 12 && b >= 1 a <= 12 a 12 a >= 1 a 1 b <= 12 b 12 b >= 1 b 1 {
			System.out.println("AMBIGUOUS");
		} System.out.println("AMBIGUOUS") System.out.println System.out System System.out "AMBIGUOUS" if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		} a <= 12 && a >= 1 a <= 12 a 12 a >= 1 a 1 {
			System.out.println("MMYY");
		} System.out.println("MMYY") System.out.println System.out System System.out "MMYY" if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		} b <= 12 && b >= 1 b <= 12 b 12 b >= 1 b 1 {
			System.out.println("YYMM");
		} System.out.println("YYMM") System.out.println System.out System System.out "YYMM" {
			System.out.println("NA");
		} System.out.println("NA") System.out.println System.out System System.out "NA" sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

	}
} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		String s = sc.next();

		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2, 4));

		if (a <= 12 && a >= 1 && b <= 12 && b >= 1) {
			System.out.println("AMBIGUOUS");
		} else if (a <= 12 && a >= 1) {
			System.out.println("MMYY");
		} else if (b <= 12 && b >= 1) {
			System.out.println("YYMM");
		} else {
			System.out.println("NA");
		}

		sc.close();

	}
}