import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		int s = scan.nextInt();
		int l = s / 100;
		int r = s % 100;
		if (l >= 1 && l <= 12) {
			if (r >= 1 && r <= 12) {
				System.out.println("AMBIGUOUS");
			} else {
				System.out.println("MMYY");
			}
		} else {
			if (r >= 1 && r <= 12) {
				System.out.println("YYMM");
			} else {
				System.out.println("NA");
			}
		}
	}
}
/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