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 <cstdio>
#include <stack>
#include <set>
#include <cmath>
#include <map>
#include <time.h>
#include <vector>
#include <iostream>
#include <string>
#include <algorithm>
#include <memory.h>
#include <cstdlib>
#include <queue>
#define P pair<int, int>
#define LL long long
#define LD long double
#define PLL pair<LL, LL>
#define mset(a, b) memset(a, b, sizeof(a))
#define PI acos(-1.0)
#define random(x) rand() % x
using namespace std;
const int inf = 0x3f3f3f3f;
const LL __64inf = 0x3f3f3f3f3f3f3f3f;
const int MAX = 1e5 + 5;
const int Mod = 1e9 + 7;

inline bool C(int x){
    return x > 0 && x <= 12;
}
int main()
{
    string s;
    cin >> s;
    int a = (s[0]-'0') * 10 + (s[1] - '0');
    int b = (s[2] - '0') * 10 + (s[3] - '0');
    if(!C(a) && C(b)){
        cout << "YYMM" << endl;
    }
    else if(!C(b) && C(a)){
        cout << "MMYY" << endl;
    }
    else if(C(a) && C(b)){
        cout << "AMBIGUOUS" << endl;
    }
    else cout << "NA" << endl;
    return 0;
}