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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;

const ll INF = 1LL << 60;
const int MOD = 1e9 + 7;

#define pb push_back
#define mp make_pair
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define REPR(i, b, e) for (int i = (b); i <= (e); i++)
#define DEBUG(x) cout << #x << ": " << (x) << endl
#define DEBUGA(a) cout << #a << ": "; for (const auto& v: (a)) cout << v << endl

int a, b;
int main() {
    int tmp;
    cin >> tmp;
    a = tmp / 100;
    b = tmp % 100;

    string ans;
    if (a == 0 || b == 0) {
        cout << "NA" << endl;
        return 0;
    }

    if (a > 12) {
        if (b > 12) {
            cout << "NA" << endl;
        } else {
            cout << "YYMM" << endl;
        }
    } else {
        if (b > 12) {
            cout << "MMYY" << endl;
        } else {
            cout << "AMBIGUOUS" << endl;
        }
    }
    return 0;
}