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: Wrong Answer)

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

#[fastout]
fn main() {
    input! {
        s: Chars
    };

    let mut is_mmyy = false;
    let mut is_yymm = false;
    let mut is_na = false;

    let s1 = s[0] as i32 - 48;
    let s2 = s[1] as i32 - 48;
    let s3 = s[2] as i32 - 48;
    let s4 = s[3] as i32 - 48;

    let x1 = s1 * 10 + s2;
    let x2 = s3 * 10 + s4;

    if x1 == 0 || x2 == 0 {
        is_na = true;
    }
    if x1 > 12 {
        is_yymm = true;
    }
    if x2 > 12 {
        is_mmyy = true;
    }
    if 0 < x1 && x1 < 13 && 0 < x2 && x2 < 13 {
        is_yymm = true;
        is_mmyy = true;
    }

    if is_na {
        println!("NA");
    } else if is_yymm && is_mmyy {
        println!("AMBIGUOUS");
    } else if is_mmyy {
        println!("MMYY");
    } else {
        println!("YYMM");
    }
}