judge ws =
    j 0 ws
    where
    j _ [] = "NA"
    j cnt ('O':rs) = e (cnt+1) rs
    j cnt ('X':rs) = w (cnt+1) rs
    e 3 _ = "East"
    e cnt ('O':rs) = e (cnt+1) rs
    e cnt rs = j 0 rs
    w 3 _ = "West"
    w cnt ('X':rs) = w (cnt+1) rs
    w cnt rs = j 0 rs

main = do
    ws <- getLine
    putStrLn $ judge ws