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>

using namespace std;

int main(){
    char n[4];
    cin >> n;
    int period[4] = {n[0] - '0', n[1] - '0', n[2] - '0', n[3] - '0'};
    int front = (10 * period[0]) + period[1];
    int back = (10 * period[2]) + period[3];
    if(front > 12 && back > 12){
        cout << "NA" << endl;
    }else if(front == 0 && back >12){
        cout << "NA" << endl;
    }else if(front > 12 && back ==0){
        cout << "NA" << endl;
    }else if(front ==0 && back ==0){
        cout << "NA" << endl;
    }else if(front <=12 && back > 12){
        cout << "MMYY";
    }else if(front > 12 && back <= 12){
        cout << "YYMM";
    }else{
        cout << "AMBIGUOUS";
    }

    return 0;
}