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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict'
function main(input) {
  input = input.trim().split('');
  let a = Number(input[0]+input[1])
  let b = Number(input[2]+input[3])
  if ((a < 1 || b < 1) || (a > 12 && b > 12)) {
    console.log('NA')
    return
  } else if (a < 13 && b < 13) {
    console.log('AMBIGUOUS')
    return
  } else if (a < 13) {
    console.log('MMYY')
    return
  } else {
    console.log('YYMM')
  }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));