import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();

    int prefix = Integer.parseInt(s.substring(0, 2));
    int suffix = Integer.parseInt(s.substring(2, 4));

    if (prefix >= 1 && prefix <= 12 && suffix >= 1 && suffix <= 12)
      System.out.println("AMBIGUOUS");
    else if (prefix >= 1 && prefix <= 12)
      System.out.println("MMYY");
    else if (suffix >= 1 && suffix <= 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