using System;
using System.Text.RegularExpressions;

class Program
{
    const string WIN = @"OOOO*";
    const string LOSE = @"XXXX*";
    const string E = "East";
    const string W = "West";
    const string N = "NA";
    static void Main(string[] args)
    {
        var line = Console.ReadLine();
        var idxEast = Regex.Match(line, WIN).Index;
        var idxWest = Regex.Match(line, LOSE).Index;

            if (idxEast < idxWest) Console.WriteLine(E);
            else if (idxEast > idxWest) Console.WriteLine(W);
            else Console.WriteLine(N);
    }
}