using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yukicoderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            int west = 1;
            int east = 1;
            string before = input.Substring(0,1);
            bool win = false;
            for(int i=1;i<input.Length;i++)
            {
                string temp = input.Substring(i, 1);
                if(temp=="O")
                {
                    if (before == temp)
                    {
                        east++;
                        before = temp;
                    }
                    else
                    {
                        east = 1;
                        before = temp;
                    }

                    if (east == 3)
                    {
                        Console.WriteLine("East");
                        win = true;
                        break;
                    }
                    
                }
                else
                {
                    if (before == temp)
                    {
                        west++;
                        before = temp;
                    }
                    else
                    {
                        west = 1;
                        before = temp;
                    }
                    if (west == 3)
                    {
                        Console.WriteLine("West");
                        win = true;
                        break;
                    }
                }
            }
            if(win==false)
            {
                Console.WriteLine("NA");
            }
        }

    }
}