import java.util.Scanner;
public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int mae = n/100;
    int usiro = n-mae*100;
    
    if(mae>0 && mae<=12 && usiro>0 && usiro<=12) {
    	System.out.print("AMBIGUOUS");
    }else if(mae>0 && mae<=12 && usiro==0) {
    		System.out.println("MMYY");
    }else if(mae>0 && mae<=12 && usiro>12) {
		System.out.println("MMYY");
    }else if(usiro>0 && usiro<=12 && mae==0) {
		System.out.println("YYMM");
    }else if(usiro>0 && usiro<=12 && mae>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