winner i []
    | i == 3    = "East"
    | i == -3   = "West"
    | otherwise = "NA"
winner i (x:xs)
    | i == 3    = "East"
    | i == -3   = "West"
    | x == 'O'  = if i > 0 then winner (i + 1) xs else winner 1 xs
    | otherwise = if i < 0 then winner (i - 1) xs else winner (-1) xs

main = getLine >>= putStrLn . (\x -> if length x < 3 then "NA" else winner 0 x)