#include "pch.h"
#include <iostream>
#include<fstream>
#include<iomanip>
using  namespace std;
int main()
{
	ifstream in("input.txt");
	ofstream out("output.txt");
	char x;
	int q = 0;
	if (!in)
	{
		cout << "Cant open file" << endl;
		exit(-1);
	}
	while (in >> x && q!=5)
	{
		out << x;

		switch (q)
		{
		case 0:
			if (x == 'A')
				q = 1;
			else
				q = 5;
			break;
		case 1:
			if (x == 'B' || x == 'D' || x == 'A')
				q = 2;
			else
				q = 5;
			break;
		case 2:
			if (x == 'A' || x == 'C')
				q = 3;
			else
				q = 5;
			break;
		case 3:
			if (x == 'E')
				q = 4;
			else
				q = 5;
			break;
		default: q = 5; break;
		}
		out << setw(2) << q << endl;
	}
	out << endl;
	if (q == 4)
		out << "OK" << endl;
	else
		out << "NO" << endl;
	in.close();
	out.close();
 }