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 Java7 (OpenJDK 1.7.0) (judge verdict: Wrong Answer)

import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String answer="";
    final String S=sc.next();
    char[] s=S.toCharArray();
    char[] sA={s[0],s[1]};
    char[] sB={s[2],s[3]};
    int a=Integer.parseInt(String.valueOf(sA));
    int b=Integer.parseInt(String.valueOf(sB));
    if(a==0){
      if(b<=12){
        answer="YYMM";
      }else{
        answer="NA";
      }
    }else if(b==0){
      if(a<=12){
        answer="MMYY";
      }else{
        answer="NA";
      }
    }else if(a<=12){
      if(b<=12){
        answer="AMBIGUOUS";
      }else{
        answer="MMYY";
      }
    }else{
      if(b<=12){
        answer="YYMM";
      }else{
        answer="NA";
      }
    }
    System.out.println(answer);
  }
}