import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		
		String s = stdIn.next();
		
		String initial = s.substring(0,2);
		
		int a = Integer.parseInt(initial); //前2文字を数字化
		
		String finish = s.substring(2,4);
		int b = Integer.parseInt(finish); //後ろ2文字を数字化
		
		
		if(1 <= a && a<= 12  && 1 <= b && b<= 12 ) {
			System.out.println("AMBIGUOUS");
		}else if(1 <= a && a<= 12 ) {
			System.out.println("MMYY");
		}else if(1 <= b && b<= 12 ){
			System.out.println("YYMM");
		}else {
			System.out.println("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