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 Rust (1.42.0) (judge verdict: Accepted)

#![allow(non_snake_case)]
#![allow(unused_imports)]
#![allow(unreachable_code)]

use proconio::marker::{Bytes, Chars};
use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        mut S: Chars,
    }

    let mut first = String::new();
    first.push(S[0]);
    first.push(S[1]);

    let mut second = String::new();
    second.push(S[2]);
    second.push(S[3]);

    let first: isize = first.parse().unwrap();
    let second: isize = second.parse().unwrap();

    let ans = match (first, second) {
        (1...12, 1...12) => "AMBIGUOUS",
        (1...12, _) => "MMYY",
        (_, 1...12) => "YYMM",
        _ => "NA",
    };

    println!("{}", ans);
}