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: Wrong Answer)

#include <stdio.h>
#include <string.h>
int main(){
	char s[100];

	scanf("%s",s);

	if(s[0] == '0' && s[1] <= '9' && s[1] != '0'){
		if(s[2] == '0' && s[3] <='9' && s[3] !='0'){
			printf("AMBIGUOUS\n");	
		}else if(s[2] == '1' && s[3] <= '2' && s[3] != '0'){
			printf("AMBIGUOUS\n");
		}else{
			printf("NA\n");
		}
	}else if(s[0] == '1' && s[1] <= '2' && s[1] != '0'){
		if(s[2] == '0' && s[3] <='9' && s[3] != '0'){
			printf("AMBIGUOUS\n");	
		}else if(s[2] == '1' && s[3] <= '2' && s[3] != '0'){
			printf("AMBIGUOUS\n");
		}else{
			printf("NA\n");
		}
	}else if(s[0] == '1' && s[1] > '2'){
		if(s[2] == '0' && s[3] <='9' && s[3] != '0'){
			printf("YYMM\n");	
		}else if(s[2] == '1' && s[3] <= '2' && s[3] != '0'){
			printf("YYMM\n");
		}else{
			printf("NA\n");
		}
	}else if(s[0] >1){
		if(s[2] == '0' && s[3] <='9' && s[3] != '0'){
			printf("YYMM\n");	
		}else if(s[2] == '1' && s[3] <= '2' && s[3] != '0'){
			printf("YYMM\n");
		}else{
			printf("NA\n");
		}
	}
	else{
		printf("NA\n");
	}
}