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: Wrong Answer)

#include <iostream>
#include <string>
using namespace std;
int main()
{
	string S;
	cin>>S;
	
	if((S[0]=='0'&&S[1]=='0')&&(S[2]=='0'&&S[3]=='0'))
		cout<<"NA";
	else if((S[0]=='0'||S[1]!='0')||(S[0]=='1'&&(S[1]=='0'||S[1]=='1'||S[1]=='2')))
	{
		if((S[2]=='0'||S[3]!='0')||(S[2]=='1'&&(S[3]=='0'||S[3]=='1'||S[3]=='2')))
			cout<<"AMBIGUOUS";
		else
			cout<<"MMYY";
	}
	else if(S[0]=='0'&&S[1]=='0')
	{
		if((S[2]=='0'||S[3]!='0')||(S[2]=='1'&&(S[3]=='0'||S[3]=='1'||S[3]=='2')))
			cout<<"YYMM";
		else
			cout<<"NA";
	}
	else
	{
		if((S[2]=='0'||S[3]!='0')||(S[2]=='1'&&(S[3]=='0'||S[3]=='1'||S[3]=='2')))
			cout<<"YYMM";
		else
			cout<<"NA";
	}
	return 0;
}