Problem:
Score : 200 points

Problem Statement

You have a digit sequence S of length 4. You are wondering which of the following formats S is in:

YYMM format: the last two digits of the year and the two-digit representation of the month (example: 01 for January), concatenated in this order

MMYY format: the two-digit representation of the month and the last two digits of the year, concatenated in this order

If S is valid in only YYMM format, print YYMM; if S is valid in only MMYY format, print MMYY; if S is valid in both formats, print AMBIGUOUS; if S is valid in neither format, print NA.

Constraints

S is a digit sequence of length 4.

Input

Input is given from Standard Input in the following format:

S

Output

Print the specified string: YYMM, MMYY, AMBIGUOUS or NA.

Sample Input 1

1905

Sample Output 1

YYMM

May XX19 is a valid date, but 19 is not valid as a month. Thus, this string is only valid in YYMM format.

Sample Input 2

0112

Sample Output 2

AMBIGUOUS

Both December XX01 and January XX12 are valid dates. Thus, this string is valid in both formats.

Sample Input 3

1700

Sample Output 3

NA

Neither 0 nor 17 is valid as a month. Thus, this string is valid in neither format.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner cs = new Scanner(System.in);
	String s = cs.nextLine();
    int a,b;

    a = Integer.parseInt(s.substring(0,2));
    b = Integer.parseInt(s.substring(2,4));
    String ans;
    if(0<a&&a<13&&(b==0||b>12)){
      ans = "MMYY";
    }else if((0<b&&b<13&&(a==0||a>12))){
      ans = "YYMM";
    }else if(0<a&&a<13&&0<b&&b<13){
      ans = "AMBIGUOUS";
    }else{
      ans = "NA";
    }
    System.out.println(ans);

    
  }
}