#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <utility>
#include <iomanip>
using namespace std;

int main(void) {
	string str;
	int west = 0, east = 0;
	cin >> str;
	for (int i = 0; i < str.size(); i++) {
		if (str[i] == 'O') {
			east++;
			west = 0;
		}
		else if (str[i] == 'X') {
			west++;
			east = 0;
		}
		if (west >= 3) {
			cout << "West" << endl;
			return 0;
		}
		else if(east >= 3) {
			cout << "East" << endl;
			return 0;
		}
	}
	cout << "NA" << endl;
	return 0;
}