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 C++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#define ll long long int
#define yorn(f) cout<<((f)?"Yes":"No")<<endl;
#define YORN(f) cout<<((f)?"YES":"NO")<<endl;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define put(x) cout << x << endl;
#define println(x) cout << x << endl;
using namespace std;
signed main()
{
    string s;
    cin >> s;
    int a = atoi(s.substr(0, 2).c_str());
    int b = atoi(s.substr(2).c_str());

    if (1 <= a && a <= 12 && (b == 0 || 13 <= b) ){
        put("MMYY");
        return 0;
    }

    if (1 <= b && b <= 12 && (a == 0 || 13 <= a)) {
        put("YYMM");
        return 0;
    }

    if ((a >= 13 || a == 0) && (b >= 13 || b == 0)) {
        put("NA");
        return 0;
    }

    put("AMBIGUOUS")

    return 0;
}