import java.util.*;
public class Main {
    private static void prin(String ans){
    System.out.println(ans);
    }

	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
        int upp = N/100;
        int downn = N%100;
        boolean my = ((1<=upp)&&(upp<=12));
        boolean ym = ((1<=downn)&&(downn<=12));
        
        if (my&&ym)
          prin("AMBIGUOUS");
        else if(my)
          prin("MMYY");
        else if(ym)
          prin("YYMM");
        else
          prin("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