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)

typedef long long ll;
#include <bits/stdc++.h>
using namespace std;
template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val){
    std::fill( (T*)array, (T*)(array+N), val );
}

int main() {
    ll s;
    std::cin >> s;
    ll a,b;
    
    bool yymm = false;
    bool mmyy = false;
    a = s/100;
    b = s%100;
    if(a<=12 && a!=0){
        mmyy = true;
    }
    if(b<=12 && b!=0){
        yymm = true;
    }
    if( mmyy && yymm){
        std::cout << "AMBIGUOUS" << std::endl;
    }else if(mmyy){
        std::cout << "MMYY" << std::endl;
    }else if(yymm){
        std::cout << "YYMM" << std::endl;
    }else{
        std::cout << "NA" << std::endl;
    }
}