use strict;
use warnings;
use utf8;

sub check {
    my $list = shift;
    my $index = shift;
    for my $n (1..2){
        if($list->[$index] ne $list->[$index + $n]){
            return undef;
        }
    }
    return 1;
}

sub solver {
    my $list = shift;
    return 'NA' if (scalar @$list) <= 1;
    my $max = (scalar @$list) - 2;
    for my $c (0..$max){
        my $ans = ($list->[$c] eq 'O') ? 'East' : 'West';
        if(check($list,$c)){
             return $ans;
        }
    }
    return 'NA';
}

chomp(my $input = <STDIN>);
my @data = split //, $input;
print solver(\@data),"\n";