import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No00000486_Main {
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	public static void main(String[] args) throws IOException {
		String s = br.readLine();
		int oi = s.indexOf("OOO");
		int xi = s.indexOf("XXX");
		if(oi == -1 && xi == -1) {
			System.out.println("NA");
		} else {
			if(oi == -1 || xi < oi) {
				System.out.println("West");
			} else {
				System.out.println("East");
			}
		}
	}
}