import java.util.Scanner;
public class Tatakai {
	
	public static void main(String args[]){
		
		Scanner sc = new Scanner(System.in);
		
		int west = 0;
		int east = 0;
		
		String str = sc.next();
		
		for(int i=0; i<str.length(); i++){
			if(str.charAt(i) == 'X'){
				east = 0;
				west++;
				if(west>=3){
					System.out.println("West");
					return;
				}
			}
			if(str.charAt(i) == 'O'){
				east++;
				west = 0;
				if(east>=3){
					System.out.println("East");
					return;
				}
			}
			
		}
		System.out.println("NA");
	}
}