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<bits/stdc++.h>
using namespace std;
typedef long long int ll;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    string str;
    cin>>str;
    ll year,month,a,b;
    a=(str[0]-'0')*10+(str[1]-'0');
    b=(str[2]-'0')*10+(str[3]-'0');
    if(a==0 && b==0)
        cout<<"NA"<<endl;
    else if(a==0 && b!=0){
        if(b<=12)
            cout<<"YYMM"<<endl;
        else
            cout<<"NA"<<endl;
    }
    else if(a!=0 && b==0){
        if(a<=12)
            cout<<"MMYY"<<endl;
        else
            cout<<"NA"<<endl;
    }
    else{
        if(a<=12 && b<=12)
            cout<<"AMBIGUOUS"<<endl;
        else if(a>12 && b<=12)
            cout<<"YYMM"<<endl;
        else if(b>12 && a<=12)
            cout<<"MMYY"<<endl;
        else
            cout<<"NA"<<endl;
    }
    return 0;
}