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>

using namespace std;

#define lp(i,n) for(int i = 0; i <n;i++)
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define MP make_pair
#define SZ(v) ((int)((v).size()))
typedef long long ll;

const ll MOD = 1e9 + 7;
const int OO = (int)1e6;
const int N = (int)1e7;

void init(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main() {
	#   ifdef LOCAL_PROJECT
        freopen("in.txt", "r", stdin);
    #   endif
    string t;
    cin>>t;
    int f=t[0]-'0';
    int s=t[1]-'0';
    int th=t[2]-'0';
    int fo =t[3]-'0';
    if(f*10+s>0&&f*10+s<13&&th*10+fo>0&&th*10+fo<13){
        cout<<"AMBIGUOUS";
    }else if(f*10+s>0&&f*10+s<13){
        cout<<"MMYY";
    }else if(th*10+fo>0&&th*10+fo<13){
        cout<<"YYMM";
    }else{
        cout<<"NA";
    }
  
    
    return 0;
}