import java.util.Scanner;

public class Main{

    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);

        // input
        int num = scan.nextInt();
        int first = num / 100;
        int last = num % 100;
        
        // search
        String answer = "NA";
        if(last >= 1 && last <= 12 && first >= 1 && first <= 12){
            answer = "AMBIGUOUS";
        } else if (last >= 1 && last <= 12){
            answer = "YYMM";
        } else if (first >= 1 && first <= 12){
            answer = "MMYY";
        }

        // answer
        System.out.println(answer);


    }
}
/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