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: Wrong Answer)

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <set> 
#include <map>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstring>
#define REP(i,n) for(int i=0; i<(n); ++i)
#define FOR(i, a, b) for(int i=(a); i<(b); ++i)
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;

int main () {

    int n; cin >>n;

    int f = n/100;
    int s = n - f*100;

    if(f == 0 || s == 0) {
        cout << "NA" << endl;
        return 0;
    } 
    if(f > 12 && s > 12) {
        cout << "NA" << endl;
        return 0;
    } 

    if(f <= 12) {
        if(s <= 12) {
            cout << "AMBIGUOUS" << endl;
            return 0;
        } else {
            cout << "MMYY" << endl;
            return 0;
        } 
    } 

    if(f > 12) {
        if(s <= 12) {
            cout << "YYMM" << endl;
            return 0;
        } 
    } 

    return 0;
}