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>
#include <string.h>
#include <stdlib.h>
#include <math.h>

int main(){
	
	char s[4];
	int b[2];
	int i;
	
	scanf("%s", &s);
	
	for(i = 0; i < 2; i++){
		if(s[i * 2] >= '2' || (s[i * 2] == '1' && s[i * 2 + 1] >= '3') || (s[i * 2] == '0' && s[i * 2 + 1] == '0'))
			b[i] = 0;
		else
			b[i] = 1;
	}
	
	if(b[0] == 1){
		if(b[1] == 1)
			printf("AMBIGUOUS");
		else
			printf("MMYY");
	}else{
		if(b[1] == 1)
			printf("YYMM");
		else
			printf("NA");
	}
	
	return 0;
}