import java.util.*;
public class Main{
	public static void main(String arg[]){
		Scanner sc=new Scanner(System.in);
		int a=sc.nextInt();
		int f=a/100;
		int l=a%100;
		String ans="NA";
		if((l>=1&&l<=12)&&(f>=1&&f<=12))
			ans="AMBIGUOUS";
		else if(l>=1&&l<=12)
			ans="YYMM";
		else if(f>=1&&f<=12)
			ans="MMYY";
		System.out.println(ans);

	}
}
/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