using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        string S = Console.ReadLine();

        int east = S.IndexOf("OOO");
        int west = S.IndexOf("XXX");

        if (0 <= west && (west < east || east < 0))
        {
            Console.WriteLine("West");
        }
        else if (0 <= east && (east < west || west < 0))
        {
            Console.WriteLine("East");
        }
        else
        {
            Console.WriteLine("NA");
        }
    }
}