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: Wrong Answer)

# include <bits/stdc++.h>
using namespace std;
int main ()
{
  string s;
  cin>>s;
  int a=(s[0]-'0')*10+s[1]-'0';
  int b=(s[2]-'0')*10+s[3]-'0';
  if (a!=0&&b!=0)
    {
      if (a>12&&b>12)
		printf ("NA\n");
	  else if((a>12&&b<=12))
	     printf("YYMM\n");
	  else if ((b>12&&a<=12))
	     printf ("MMYY\n");
	  else if (a<=12&&b<=12)
	     printf ("AMBIGUOUS\n");  
	}	
   else
    {
    	if ((a==0&&b<=12&&b!=0)||(b==0&&a<=12&&a!=0))
    	  	printf("YYMM\n");
		else if ((a==0&&b>12)||(b==0&&a>12)||(a==0&&b==0))
		   printf ("NA\n");
	}
  return 0;	
}