#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  string S;
  cin >> S;
  int east = 0, west = 0;
  for (auto s : S) {
    if (s == 'O') {
      east++;
      west = 0;
    }
    if (s == 'X') {
      west++;
      east = 0;
    }
    if (east == 3 || west == 3) break;
  }
  if (west == 3) {
    cout << "West" << '\n';
  } else if (east == 3) {
    cout << "East" << '\n';
  } else {
    cout << "NA" << '\n';
  }
  return 0;
}