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;


int main()
{
    string S;
    int a,b;
    cin >> S;
    a = atoi(S.substr(0,2).c_str());
    b = atoi(S.substr(2,2).c_str());

 

    if(a > 12 || a == 0){ //YY
        if(b > 12 || b == 0)
        {
            cout << "NA" << endl;
        }else{
            cout << "YYMM" << endl;
        }
    }else{ // MM or YY

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

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

}