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<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<math.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.size();
  string y = s.substr(0,2);
  string m = s.substr(2,2);
  
  int yy = stoi(y);
  int mm = stoi(m);
  
  if (mm >= 1 && mm <= 12) {
    if (yy >= 1 && yy <= 12) {
      cout << "AMBIGUOUS" << endl;
    }
    if (yy > 12 && yy == 0) {
      cout << "YYMM" << endl;
    }
  }
  if (yy >= 1 && yy <= 12) {
    if (mm == 0 && mm > 12) {
      cout << "MMYY" << endl;
    }
  }
  if (mm == 0 && yy > 12 || yy == 0 && mm > 12) {
    cout << "NA" << endl;
  }
}