import java.util.Scanner;
public class Main {
	public static void main(String args[]) {
		Scanner stdIn = new Scanner(System.in);
		int n = stdIn.nextInt();

		int a = n % 100;
		int b = (n - a) / 100;

		boolean um = false;
		boolean sm = false;

		if(0 < a && a < 13) um = true;
		if(0 < b && b < 13) sm = true;

		if(um && sm) System.out.println("AMBIGUOUS");
		else if(um) System.out.println("YYMM");
		else if(sm) System.out.println("MMYY");
		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