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 9.2.1) (judge verdict: Accepted)

#include<iostream>
using namespace std;

int main(){
  char a,b,c,d;
  cin>>a>>b>>c>>d;
  if((a=='0' && b>='1' && b<='9')||(a=='1' && b>='0' && b<='2')){
    if((c=='0' && d>='1' && d<='9')||(c=='1' && d>='0' &&d<='2'))
    cout<<"AMBIGUOUS";
    else
    cout<<"MMYY";
  }
  else if((c=='0' && d>='1' && d<='9')||(c=='1' && d>='0' &&d<='2'))
  cout<<"YYMM";
  else
  cout<<"NA";
  return 0;
}