import java.util.Scanner;


public class Main {
    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        String line = stdin.nextLine();
        
        int east = line.indexOf("OOO");
        int west = line.indexOf("XXX");
        
        if (east == -1 && west == -1) {
            System.out.println("NA");
        } else if (east < west) {
            System.out.println("East");
        } else {
            System.out.println("West");
        }
    }
}