import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String mymy = s.next();
        String first = mymy.substring(0, 2);
        String second = mymy.substring(2, 4);
        int fi = Integer.parseInt(first);
        int se = Integer.parseInt(second);
        String alg;
        if (0 < fi && fi <= 12) {
            if (0 < se && se <= 12) alg = "AMBIGUOUS";
            else alg = "MMYY";
        } else {
            if (0 < se && se <= 12) alg = "YYMM";
            else alg = "NA";
        }
        System.out.println(alg);
    }
}
/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