import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int S = sc.nextInt();
		boolean l = 1 <= S / 100 && S / 100 <= 12, r = 1 <= S % 100 && S % 100 <= 12;
		if (l && r) System.out.println("AMBIGUOUS");
		else if (l && !r) System.out.println("MMYY");
		else if (!l && r) 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