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 <string>
using namespace std;

int main()
{
    string s;
    cin>>s;
    bool b1,b2;
    b1=false;
    b2=false;
    if((s[0]=='1' && ((int)s[1]>=48 && (int)s[1]<=50))|| (s[0]=='0' &&(int)s[1]>=49 &&(int)s[1]<=57)){
        b1=true;
    }
    if((s[2]=='1' && ((int)s[3]>=48 && (int)s[3]<=50))|| (s[2]=='0' &&(int)s[3]>=49 &&(int)s[3]<=57)){
    	b2=true;
    } 
    if(b1&&b2){
    	cout << "AMBIGUOUS" << endl;
        return 0;
    }else if(b1){
    	cout << "MMYY" << endl;
        return 0;
    }else if(b2){
    	cout << "YYMM" << endl;
        return 0;
    }else{
    	cout << "NA" << endl;
        return 0;
    }

}