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 <algorithm>
#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<string>

#include<stdlib.h>
#include<string.h>
#include<math.h>
#include<limits.h>

using namespace std;
bool isMM(int mm){
  if(mm >= 1 && mm <= 12){
    return true;
  }
  else{
    return false;
  }
}
int main(){
  string s;
  string sMae,sAto;
  cin >> s;
  int mae,ato;
  sMae = s.substr(0,2);
  sAto = s.substr(2,2);
  //cout << sMae << endl;
  //cout << sAto <<endl;
  mae = atoi(sMae.c_str());
  ato = atoi(sAto.c_str());
  if(isMM(mae) && isMM(ato)){
    cout << "AMBIGUOUS" << endl;
  }
  else if(isMM(mae) && !isMM(ato)){
    cout << "MMYY" << endl;
  }
  else if(!isMM(mae) && isMM(ato)){
    cout << "YYMM" << endl;
  }
  else{
    cout << "NA" << endl;
  }
  return 0;
}