import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int S = sc.nextInt();
        int n[] = new int[2];
        int d = 100;
      
     for (int i = 0; i < 2; i++) {n[i]=(S/d);S%=d;d/=100;}
     if(n[1]>00&&n[1]<13){
        if(n[0]>00&&n[0]<13){System.out.print("AMBIGUOUS");}
       else{System.out.print("YYMM");}
     }
     else if(n[0]>00&&n[0]<13){System.out.print("MMYY");}
     else{System.out.print("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