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++ (GCC 9.2.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;

// for loop
#define rep(i,a,n) for(int i=(a);i<(n);++i)
#define repe(i,a,n) for(int i=(a);i<=(n);++i)
#define rrep(i,n,a) for(int i=(n);n>(a);--i)
#define rrepe(i,n,a) for(int i=(n);n>=(a);--i)

// abbreviati
#define PB(v) push_back(v)
#define MP(A,B) make_pair(A,B)
#define F first
#define S second
#define all(v) v.begin(),v.end()
#define ENDL << "\n"

using ll = long long;
using P = pair<int,int>;
using itn = int;

// constant
const int INF = 1<<30;
const ll INFLL = 1LL << 60;
const ll MOD = 1000000007;
const long double PI =(acos(-1));

/***Snippet***************************************************
ifelse, isprime, torad, todeg, lcm, bfs,chmin,chmax
**************************************************************/

// adjacency list
vector<int> to[100005];

// Graph
using Graph = vector<vector<int>>;

// Grid
int H,W;
vector<vector<int>> field;

// 4方向への移動ベクトル
const int dx[4]={1,0,-1,0};
const int dy[4]={0,1,0,-1};


int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string s; cin >> s;
    int LL=(int)(s[0]-48)*10+(int)(s[1]-48); 
    int RR=(int)(s[2]-48)*10+(int)(s[3]-48); 
    
    if(1<=RR && RR<=12 && 1<=LL && LL<=12) cout << "AMBIGUOUS" ENDL;
    else if(RR>=0 && 1<=LL && LL<=12) cout << "MMYY" ENDL;
    else if(1<=RR && RR<=12 && LL>=0) cout << "YYMM" ENDL; 
    else cout << "NA" ENDL;    
    return 0;
}