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

namespace yukicoder_486 {
    class Program {
        static void Main(string[] args) {
            string s = Console.ReadLine();
            int east = s.IndexOf("OOO");
            int west = s.IndexOf("XXX");
            if (east < 0 && west < 0) {
                Console.WriteLine("NA");
            }else if (east < 0) {
                Console.WriteLine("West");
            }else if (west < 0) {
                Console.WriteLine("East");
            } else {
                if (east < west) {
                    Console.WriteLine("East");
                } else {
                    Console.WriteLine("West");
                }
            }
            Console.ReadLine();
        }
    }
}