#include <iostream>
#include <string>

using namespace std;

int main(int argc, const char* argv[])
{
	int a, b;
	string s;

	cin >> s;

	int n	= s.length();
	int west = 0;
	int east = 0;
	for (int i = 0; i < n; i++) {
		char c = s.at(i);
		if (c == 'O') {
			east++;
			west = 0;
		}
		if (c == 'X') {
			west++;
			east = 0;
		}
		if (east == 3) {
			cout << "East" << endl;
			return 0;
		}
		if (west == 3) {
			cout << "West" << endl;
			return 0;
		}
	}

	cout << "NA" << endl;
	return 0;
}