import java.util.*;
class Main{
     public static void main(String []args){
        Scanner sc= new Scanner(System.in);
        int S=sc.nextInt();
        if(S<0){
                System.out.println("NA");
                return;
            }
        if(S%100<13&&S%100!=0){
            
            if(S/100<13&&S/100!=0){
                System.out.println("AMBIGUOUS");
                return;
            }
            System.out.println("YYMM");
            return;
        }
        if(S/100<13&&S/100!=0){
            System.out.println("MMYY");
        
            return;
        }
        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