using System.Collections.Generic;
using System;
using System.Drawing;
namespace yukicoder
{
    class Program
    {

        static void Main(string[] args)
        {
            var S = Console.ReadLine();
            string[] str = new string[S.Length];

            for (int i = 0; i < S.Length - 2; i++)
            {
                if (S.Length < 3)
                {
                    Console.WriteLine("NA");
                    break;
                }
                str[i] = S.Substring(i, 3);
                if (str[i] == "OOO")
                {
                    Console.WriteLine("East");
                    break;
                }
                else if (str[i] == "XXX")
                {
                    Console.WriteLine("West");
                    break;
                }
                else if (i == S.Length - 3)
                {
                    Console.WriteLine("NA");
                    break;
                }
            }
            if (S.Length < 3)
            {
                Console.WriteLine("NA");
            }
        }
    }
}