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 <bits/stdc++.h>
#define ll long long
#define all(a) (a).begin(), (a).end()
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define sz() size()
#define fr first
#define sc second
#define pb push_back
#define er erase
#define in insert
#define pi pair<int,int>
#define pii pair<pair<int,int>,int>
#define mp make_pair
#define int long long
#define rc(s) return cout<<s,0
//#define cin fin
//#define cout fout
using namespace std;


const int nmax=1e3+5;
const int mod=1e9+7;
const int mod1=998244353;

int n,k;
string s;

bool check(int i1,int i2){
    if((s[i1]=='0' && s[i2]>='1') || (s[i1]=='1' && s[i2]>='0' && s[i2]<='2')) return true;
    return false;
}

int32_t main(){
    ios_base::sync_with_stdio(0);cin.tie();cout.tie();
    cin >> s;
    if(check(0,1)==true && check(2,3)==true) rc("AMBIGUOUS");
    else if(check(0,1)==true && check(2,3)==false) rc("MMYY");
    else if(check(0,1)==false && check(2,3)==true) rc("YYMM");
    else rc("NA");
}