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 (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>

int main()
{
	int S[4], flag = 0; //flag=0はNA 1はMMYY 2はYYMM 3がAMBIGUOUS
		scanf("%1d%1d%1d%1d", &S[0],&S[1],&S[2],&S[3]);

	if ((S[0] >= 1 && S[1] > 2) || (S[0]>1) || (S[0]==0 && S[1]==0)) {
		if ( (S[2] >= 1 && S[3] > 2) || (S[2]==0&&S[3]==0) || (S[2]>1) || (S[2]==0 && S[3]==0)) {
			flag = 0;
		}
		else {
			flag = 2;
		}
	}else if ((S[2] >= 1 && S[3] > 2) || (S[2]>1) || (S[2]==0 && S[3]==0)) {
		flag = 1;
	}
	else {
		flag = 3;
	}

	switch (flag) {
	case 0:
		puts("NA");
		break;
	case 1:
		puts("MMYY");
		break;
	case 2:
		puts("YYMM");
		break;
	case 3:
		puts("AMBIGUOUS");
		break;
	}

	return 0;
}