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>
#include <string.h>

int main(void)
{
  char S[5], X[3], Y[3];
  int XisMM, YisMM;
  XisMM = 0;
  YisMM = 0;
  scanf("%s", S);
  X[0]=S[0];
  X[1]=S[1];
  X[2]=0x00;
  Y[0]=S[2];
  Y[1]=S[3];
  Y[2]=0x00;
  
  if (atoi(X)>=1 && atoi(X)<=12) XisMM = 1;
  if (atoi(Y)>=1 && atoi(Y)<=12) YisMM = 1;
  
  if (XisMM && !YisMM) {
    printf("MMYY\n");
  } else if (!XisMM && YisMM) {
    printf("YYMM\n");
  } else if (XisMM && YisMM) {
    printf("AMBIGUOUS\n");
  } else {
    printf("NA\n");
  }
}