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;

int main() {
  string input;
  cin >> input;
  int N;
  N = input.length();

  int a[N];
  for(int i=0;i<N;++i){
    a[i] = (int)(input[i] - '0');
  }

  bool flug1 = false;
  bool flug2 = false;

  if(a[0]*10+a[1]<13 && a[0]*10+a[1]>0) flug1 = true;
  if(a[2]*10+a[3]<13 && a[2]*10+a[3]>0) flug2 = true;

  if(flug1){
    if(flug2) cout << "AMBIGUOUS" << endl;
    else cout << "MMYY" << endl;
  }

  else if(flug2) cout << "YYMM" << endl;

  else cout << "NA" << endl;

}