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: Accepted)

#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int main(){
    int n,a,b;
    bool YYMM_flag=false,MMYY_flag=false;

    cin>>n;
    a=n/100;
    b=n%100;
    //cout<<"a: "<<a<<" b: "<<b<<endl;
    if(a==0){
        MMYY_flag=false;
        if(b<=12 && b>0){
            YYMM_flag=true;
        }
    }else if(b==0){
        YYMM_flag=false;
        if(a<=12 && a>0){
            MMYY_flag=true;
        }
    }else if(a>12){
        MMYY_flag=false;
        if(b<=12){
            YYMM_flag=true;
        }
    }else if(a<=12 && b>12){
        MMYY_flag=true;
    }else{
        YYMM_flag=true;
        MMYY_flag=true;
    }
    
    if(YYMM_flag && MMYY_flag){
        cout<<"AMBIGUOUS"<<endl;
    }else if(YYMM_flag){
        cout<<"YYMM"<<endl;
    }else if(MMYY_flag){
        cout<<"MMYY"<<endl;
    }else{
        cout<<"NA"<<endl;
    }

    return 0;
}