import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s=sc.next();
        int west=101;
        int east=101;

        String reg="OOO";
        Pattern p=Pattern.compile(reg);
        Matcher m=p.matcher(s);
        if (m.find()){
            east=m.start();
        }

        reg="XXX";
        p=Pattern.compile(reg);
        m=p.matcher(s);
        if (m.find()){
            west=m.start();
        }

        if(east==west){
            System.out.println("NA");
        }else if(east<west){
            System.out.println("East");
        }else{
            System.out.println("West");
        }
    }
}