
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;

class Main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int a = Integer.parseInt(s.substring(0, 2));
		int b = Integer.parseInt(s.substring(2));
		
		String ans = "NA";
		if ((a >= 1 && a<= 12) && (b >= 1 && b<= 12)) {
			ans = "AMBIGUOUS";
		} else if (a >= 1 && a<= 12) {
			ans = "MMYY";
		} else if (b >= 1 && b<= 12) {
			ans = "YYMM";
		} 
		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