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 <vector>
#include <string>
#include <cstring>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <unordered_map>
#include <cmath>
#include <utility> // pair make_pair
#include <algorithm>
#include <functional>
#include <iomanip>
#include <climits> // LLONG_MAX, LLONG_MIN, INT_MIN, INT_MAX
#include <assert.h>

#define m0(x) memset(x,0,sizeof(x))
#define m1(x) memset(x,63,sizeof(x))
#define fill(x,y) memset(x,y,sizeof(x))
#define ll long long
//#define int ll
#define INF INT_MAX/10
#define MOD 1000000007

using namespace std;
using Pi = pair<int, int>;
using Graph = vector<vector<int> >;
using WeightGraph = vector<vector<Pi> >;

int Input[100100];

int main() {
  string S; cin >> S;
  int x = stoi(S.substr(0, 2));
  int y = stoi(S.substr(2, 2));
  if( (x > 12 || x < 1) && ( y > 12 || y < 1)) {
    cout << "NA" << endl;
  } else if (x > 12 || x < 1) {
    cout << "YYMM" << endl;
  } else if (y > 12 || y < 1) {
    cout << "MMYY" << endl;
  } else {
    cout << "AMBIGUOUS" << endl;
  }
}