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 (Clang 3.8.0) (judge verdict: Accepted)

// Last Change: 05/19/2019 21:12:35.
#include <algorithm>
#include <array>
#include <bitset>
#include <cmath>
#include <cstdlib>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;
using ll = long long;

namespace NS {
void LoopUntilZeroInpput() {
  int hogegegege = 0;
  while (cin >> hogegegege && hogegegege != 0) {
  }
}
} // namespace NS

bool CheckYY(int ipt) {
  return 1;
}

bool CheckMM(int ipt) {
  if (0 < ipt and 13 > ipt) {
    return true;
  } else {
    return false;
  }
}

int main() {
  int S, left, right;
  cin >> S;
  left = S / 100;
  right = S % 100;

  bool YYMM, MMYY;
  YYMM = MMYY = false;

  if (CheckYY(left) and CheckMM(right)) {
    YYMM = true;
  }
  if (CheckYY(right) and CheckMM(left)) {
    MMYY = true;
  }

  if (YYMM) {
    if (MMYY) {
      cout << "AMBIGUOUS" << endl;
    } else {
      cout << "YYMM" << endl;
    }
  } else {
    if (MMYY) {
      cout << "MMYY" << endl;
    } else {
      cout << "NA" << endl;
    }
  }

  //NS::LoopUntilZeroInpput();
}