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>
using namespace std;
int main() {
	int S,F,A;
	int Y,M;

	cin >> S;
	F = (int)S / 100;
	A = S - F * 100;
		if (F <= 12 && F >= 1) {
			M = 1; //月かも
		}
		else {
			M= 3; //年確定
		}
		if (A <= 12 && A >= 1) {
			Y = 2; //月かも
		}
		else {
			Y = 5; //年確定
		}
		switch (M + Y){
			case 3:
				cout << "AMBIGUOUS" << endl;
			break;
			case 6:
				cout << "MMYY" << endl;
				break;
			case 5:
				cout << "YYMM" << endl;
			break;

			case 8:
				cout << "NA" << endl;
			break;
		}
		return 0;
}