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: Accepted)

#include <cstring>
#include <sstream>
#include <cstdio>
#include <algorithm>
#include <iostream>
#include <vector>
#include <iomanip>
#include <map>
#include <unordered_map>
#include <cmath>
#include <queue>
#include <set>
#include <numeric>
#include <stack>

using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0; i < (ll)(n); i++)
#define repr(i, n) for(ll i = n - 1; i >= 0; i--)
#define repone(i, n) for(ll i = 1; i <= (ll)(n); i++)
#define each(i, mp) for(auto i:mp)
#define eb emplace_back
#define F first
#define S second
#define all(obj) (obj).begin(), (obj).end()
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ll mod = 1000000007;
const ll inf = ll(1e9);
const ll half_inf = ll(1e5);
const ll ll_inf = ll(1e9) * ll(1e9);
typedef unordered_map<ll, ll> mpll;
typedef unordered_map<char, ll> mpcl;
typedef unordered_map<string, ll> mpsl;
typedef pair<ll, ll> P;
typedef vector<ll> vl;
typedef vector<vl> vvl;
template<typename T> using PQ = priority_queue<T>;
template<typename T> using minPQ = priority_queue<T, vector<T>, greater<T>>;

ll inl() {
    ll x;
    cin >> x;
    return (x);
}

string ins() {
    string x;
    cin >> x;
    return (x);
}

int main() {
#ifdef MY_DEBUG
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wmissing-noreturn"
    while (true) {
#pragma clang diagnostic pop
#endif
        string s = ins();
        int up2 = (s[0] - '0') * 10 + (s[1] - '0');
        int low2 = (s[2] - '0') * 10 + (s[3] - '0');

        if (low2 == 0) {
            if (up2 >= 1 && up2 <= 12) cout << "MMYY" << endl;
            else cout << "NA" << endl;

        } else if (up2 == 0) {
            if (low2 <= 12) cout << "YYMM" << endl;
            else cout << "NA" << endl;

        } else if (up2 <= 12) {
            if (low2 <= 12) cout << "AMBIGUOUS" << endl;
            else cout << "MMYY" << endl;

        } else {
            if (low2 <= 12) cout << "YYMM" << endl;
            else cout << "NA" << endl;
        }


#ifdef MY_DEBUG
    }
#endif
    return 0;
}