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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.*

fun main(args:Array<String>){
    val s = readLine()!!
    val a = Integer.parseInt(s.substring(0, 2))
    val b = Integer.parseInt(s.substring(2,4))
    println(
    if((a == 0 && b == 0) || (a > 12 && b > 12)){
        "NA"
    }
    else if(a == 0){
        if(b > 12) "NA"
        else "YYMM"
    }
    else if(b == 0){
        if(a > 12) "NA"
        else "MMYY"
    }
    else if(a <= 12 && b <= 12){
        "AMBIGUOUS"
    }
    else if(a > 12){
        "YYMM"
    }
    else if(b > 12){
        "MMYY"
    }
    else{
        "NA"
    })
}