#include<iostream>
#include<string>
using namespace std;

int main()
{
    string s;
    cin>>s;
    if(s.length()<3){ cout << "NA" << endl; }
    else {
        int east = s.find("OOO");
        int west = s.find("XXX");
        if(west==-1 && east==-1){ cout << "NA" << endl; }
        else if(west==-1) { cout << "East" << endl; }
        else if(east==-1) { cout << "West" << endl; }
        else if(west>east) { cout << "East" << endl; }
        else if(west<east) { cout << "West" << endl; }
    }
    
    return 0;
}