fn hantei(ss: &mut String) -> String {
    let east = ss.find("OOO");
    let west = ss.find("XXX");

    (if east.is_none() && west.is_none() {
        "NA"
    }
    else if east.is_none() {
        "West"
    }
    else if west.is_none() {
        "East"
    }
    else if east.unwrap() < west.unwrap() {
        "East"
    }
    else {
        "West"
    }).to_string()
}

fn getline() -> String {
    let mut s = String::new();

    std::io::stdin().read_line(&mut s).ok();

    s
}

fn main() {
    let mut s = getline();

    println!("{}", hantei(&mut s));
}