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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class Program
{
    static void Main(string[] args)
    {
        List<int> num = new List<int>();
        for(int i = 0; i < 4; i++)
        {
            int a = Console.Read();
            a -= 48;
            num.Add(a);
        }
        int mae = num[0] * 10 + num[1];
        int usiro = num[2] * 10 + num[3];
        if (1 <= mae && mae <= 12) mae = 1;
        else mae = 0;
        if (1 <= usiro && usiro <= 12) usiro = 1;
        else usiro = 0;
        if (mae == 1 && usiro == 1) Console.WriteLine("AMBIGUOUS");
        else if (mae == 1 && usiro == 0) Console.WriteLine("MMYY");
        else if (mae == 0 && usiro == 1) Console.WriteLine("YYMM");
        else if (mae == 0 && usiro == 0) Console.WriteLine("NA");
    }
}