import java.util.*;

public class No_486{
	public static void main(String[] args){
		String Str;
		int West=0,East=0;
		Scanner scanner = new Scanner(System.in);
		scanner.close();
		Str  = scanner.next();
		for(int i=0;i<Str.length();i++){ 
			if(Str.charAt(i) == 'O'){
				East=0;
				West++;
				if(West>=3){ System.out.println("East"); return;}
			}
			if(Str.charAt(i)=='X'){
				West=0;
				East++;
				if(East>=3){ System.out.println("West"); return;}
			}
		}
		System.out.println("NA");
	}
}