import java.util.Scanner;

public class EWgame {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String str = sc.next();
		char[] c = new char[str.length()];
		for(int i = 0;i<str.length();i++){
			c[i] = str.charAt(i);
		}
		
		int east = 0,west = 0;
		for(int i = 0;i < str.length();i++){
			if(c[i] == 'O'){
				east++;
				west = 0;
				if(east >= 3){
					System.out.println("East");
					break;
				}
			}else if(c[i] == 'X'){
				east = 0;
				west++;
				if(west >= 3){
					System.out.println("West");
					break;
				}
			}
		}
		if(east<3 && west < 3){
			System.out.println("NA");
		}

	}

}