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>
#include <array>
#define FOR(i,a,b) for(int i=(a);i<=(b);++i) 
#define RFOR(i,a,b) for(int i=(a);i>=(b);--i) 
#define REP(i,n) for(int i=0;i<(n);++i)
#define RREP(i,n) for(int i=(n);i>0;--i)
#define CI cin>> 
#define CO cout<<
#define EN <<endl 
#define all(x) (x).begin(),(x).end() 
using namespace std;
template <typename T> istream & operator >> (istream & is, vector<T> & vec) { for (T& x : vec) is >> x; 	return is; }
using ll = long long;
using VI = vector<int>;
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }

int main() {
	int a; CI a;

	if (a % 100 == 0&&a/100>12) { CO "NA" EN; return 0; }
	if (a % 100 == 0 && a / 100 <= 12&&a/100>0) { CO "MMYY" EN; return 0; }
	if(a%100>12&&a/100>12){ CO "NA" EN; return 0; }
	if (a / 100 == 0 && a % 100 <= 12&&a%100>0) { CO "YYMM" EN; return 0; }
	if (a / 100 == 0 && a % 100 > 12) { CO "NA"  EN; return 0; }
	if (a / 100 == 0 && a % 100 == 0) { CO "NA" EN; return 0; }

	if (a / 100 <= 12) {
		if (a % 100 != 0) {
			if (a % 100 > 12) { CO "MMYY" EN; }
			else CO "AMBIGUOUS" EN;
		}
	}
	else {
		CO "YYMM" EN;
		return 0;
	}

	return 0;
}