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<stdlib.h>

char judge(int x){
    int a, b;
    int year = 0;
    int month = 0;

    if((x >= 0) && (x <= 99)) {
        year = 1;
    }
    if ((x >= 1) && (x <=12)){
        month = 1;
    }

    if(year * month == 1) {
        return 'a';
    }
    if((year == 1) && (month == 0)) {
        return 'y';
    }
    if((month == 1) && (year == 0)) {
        return 'm';
    }
    else{
        return 'n';
    }
}


int main(void){
  char buf[4];
  scanf("%s", buf);
  int a = (int)(buf[0]-'0') * 10 + (int)(buf[1]-'0');
  int b = (int)(buf[2]-'0') * 10 + (int)(buf[3]-'0');
  char A = judge(a);
  char B = judge(b);

  if((A == 'y') && ((B == 'm') || (B == 'a'))) {
      printf("YYMM\n");
      return 0;
  }

  if((B == 'y') && ((A == 'm') || (A == 'a'))) {
      printf("MMYY\n");
      return 0;
  }

  if((A == 'a') && (B == 'a')) {
      printf("AMBIGUOUS\n");
      return 0;
  }

  else{
      printf("NA\n");
      return 0;
  }
}