import java.util.*;

public class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        Integer s = sc.nextInt();
        Integer preI = s / 100;
        Integer endI = s % 100;
        boolean isPrePossibleM = 1 <= preI && preI <=12;
        boolean isEndPossibleM = 1 <= endI && endI <=12;
        if (isPrePossibleM) {
            if (isEndPossibleM) {
                System.out.println("AMBIGUOUS");
            } else {
                System.out.println("MMYY");
            }
        } else {
            if (isEndPossibleM) {
                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