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 rep(i,n) for(int i=0;i<n;i++)
#define ll long long int
bool han(int a){
  if(1<=a&&a<=12)
    return true;
  else
    return false;
}

int main(){
  int S;
  cin>>S;
  int A,B;
  A=S/100;
  B=S-A*100;
  if(han(A)&&han(B))
    cout<<"AMBIGUOUS"<<endl;
  else if(A==0&&!han(B))
    cout<<"NA"<<endl;
  else if(B==0&&!han(A))
    cout<<"NA"<<endl;
  else if(!han(A)&&!han(B))
    cout<<"NA"<<endl;
  else if(han(A))
    cout<<"MMYY"<<endl;
  else
    cout<<"YYMM"<<endl;
  return 0;
}