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>

int main(void)
{
  int S,mmyy_flag=1,yymm_flag=1,up_2_dig,und_2_dig;
  
  scanf("%d",&S);
  up_2_dig=S/100;
  
  und_2_dig=S-up_2_dig*100;
 
  if(up_2_dig>12)
  {
    mmyy_flag=0;
  }
  
  if(und_2_dig==0)
  {
    yymm_flag=0;
  }
    
  if(und_2_dig==0 && up_2_dig==0 || und_2_dig>12 && up_2_dig>12 || und_2_dig>0 && up_2_dig>12 || und_2_dig>12 && up_2_dig>0)
  {
    yymm_flag=0;
    mmyy_flag=0;
  }
  
  if(yymm_flag==1 && mmyy_flag==1)
  {
    printf("AMBIGUOUS\n");
  }
  else if(yymm_flag==1 && mmyy_flag==0)
  {
    printf("YYMM\n");
  }
  else if(yymm_flag==0 && mmyy_flag==1)
  {
    printf("MMYY\n");
  }
  else
  {
    printf("NA\n");
  }
  
  return 0;
}