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.Scanner;

class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String S = sc.next();
        sc.close();
        String[] C = S.split("");
        String I1 = C[0] + C[1];
        String I2 = C[2] + C[3];
        int N1 = Integer.parseInt(I1);
        int N2 = Integer.parseInt(I2);
        String ans;
        if(N1 != 00 && N2 != 00){
            if(N1 <= 12){
                ans = (N2<=12)? "AMBIGUOUS" : "MMYY";
            }
            else{
                ans = (N2<=12)? "YYMM":"NA";
            }
        }
        else if(N1==00) {
            ans = (N2<=12 && N2 > 0)? "YYMM":"NA";
        }
        else if(N2==00){
            ans = (N1<=12 && N1 > 0)? "MMYY":"NA";
        }
        else {ans = "NA";}
        System.out.print(ans);
    }
}