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 (1.15.1) (judge verdict: Wrong Answer)

mod io{
    use std::io::*;
    pub fn read<T: ::std::str::FromStr>()->T{
        let stdin=stdin();
        let ret=stdin.lock().bytes().map(|c|c.unwrap()as char)
        .skip_while(|c|c.is_whitespace())
        .take_while(|c|!c.is_whitespace())
        .collect::<String>().parse().ok().unwrap();
        ret
    }
}
 
use io::read;

fn main(){
    let s: i32 = read();
    let u = s / 100;
    let d = s % 100;
    let mut yymm = false;
    let mut mmyy = false;
    let mut ans: &str;

    println!("{},{}", u, d );

    if 12 > u && u > 0 {
         mmyy = true;
    }

    if 12 > d && d > 0 {
        yymm = true;
    }

    if yymm && mmyy {
        ans = "AMBIGUOUS";
    } else if yymm {
        ans = "YYMM";
    } else if mmyy {
        ans = "MMYY";
    } else {
        ans = "NA";
    }

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