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<iostream>
#include<string>
#include<vector>
using namespace std;

int main() {
	string S;
	cin >> S;
	int tf = 0;
	if (S[0] == '0'&&S[1] != '0') tf++;
	else if (S[0] == '1' && (S[1] == '0' || S[1] == '1' || S[1] == '2')) tf++;
	if (S[2] == '0'&&S[3] != '0') tf += 2;
	else if (S[2] == '1' && (S[3] == '0' || S[3] == '1' || S[3] == '2')) tf += 2;
	if (tf == 0) cout << "NA" << endl;
	else if (tf == 1)cout << "MMYY" << endl;
	else if (tf == 2)cout << "YYMM" << endl;
	else if (tf == 3)cout << "AMBIGUOUS" << endl;

	return 0;
}