import java.util.Scanner;

public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	int S = sc.nextInt();
	int s34 = S%100;
	int s12 = S/100;

	if((1<=s12 && s12<=12) && (1<=s34 && s34<=12)){
	    System.out.print("AMBIGUOUS");
	}else if(1<=s12 && s12<=12){
	    System.out.print("MMYY");
	}else if(1<=s34 && s34<=12){
	    System.out.print("YYMM");
	}else{
	    System.out.print("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