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();

	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz