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>
#include <math.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)

const int MOD = 1000000007;

const int INF_32 = 1LL << 30;
const int64_t INF_64 = 1LL << 60;

int main()
{
    string S;
    cin >> S;
    int first = stoi(S.substr(0, 2));
    int second = stoi(S.substr(2, 2));

    string ans;
    if (first >= 1 && first <= 12 && second >= 1 && second <= 12) {
        ans = "AMBIGUOUS";
    } else if (first >= 0 && first <= 99 && second >= 1 && second <= 12) {
        ans = "YYMM";
    } else if (first >= 1 && first <= 12 && second >= 0 && second <= 12) {
        ans = "MMYY";
    } else {
        ans = "NA";
    }

    cout << ans << endl;
}