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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System ;

namespace Program{
  class Program{
   static void Main(string []args){
    string S  = Console.ReadLine() ;
    
    int left = int.Parse( "" + S[0] + S[1]) ;
    int right = int.Parse( "" + S[2] + S[3] ) ;
    
    string result = "" ;
    if( left > 0 && left <= 12 && right > 0 && right <= 12){
       result = "AMBIGUOUS" ;
    }else if( left > 12 && right > 0 && right <= 12){
       result = "YYMM" ;
    }else if( left > 0 && left <= 12 && right > 12){
       result = "MMYY" ;
    }else{
       result = "NA" ;
    }
     
    Console.WriteLine( result ) ;
   }
  }
}