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 <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vl;
#define rep(i, n) for(ll i = 0;i < n;i++)
#define all(i) i.begin(), i.end()
template<class T, class U> void cmax(T& a, U b) { if (a<b) a = b; }
template<class T, class U> void cmin(T& a, U b) { if (a>b) a = b; }

int main() {
  cin.tie(0); ios::sync_with_stdio(false);

  string s;
  cin >> s;

  int a = stoi(s.substr(0, 2));
  int b = stoi(s.substr(2, 2));
  cerr << a << " "<< b << endl;

  if (a <= 12 && a != 0) {
    if (b <= 12 && b != 0) {
      cout << "AMBIGUOUS" << endl;
    } else {
      cout << "MMYY" << endl;
    }
  } else {
    if (b <= 12 && b != 0) {
      cout << "YYMM" << endl;
    } else {
      cout << "NA" << endl;
    }
    
  }
}