open System open System.Collections.Generic [] module Cin = let read f = stdin.ReadLine() |> f let reada f = stdin.ReadLine().Split() |> Array.map f let readChars() = read string |> Seq.toArray let readInts() = readChars() |> Array.map (fun x -> Convert.ToInt32(x.ToString())) [] module Cout = let writer = new IO.StreamWriter(new IO.BufferedStream(Console.OpenStandardOutput())) let print (s: string) = writer.Write s let println (s: string) = writer.WriteLine s let inline puts (s: ^a) = string s |> println let solve() = let s = readChars() seq { for i in 0 .. s.Length - 3 do let a = sprintf "%c%c%c" s.[i] s.[i + 1] s.[i + 2] if a = "OOO" then yield "West" elif a = "XXX" then yield "East" } |> fun s -> if Seq.isEmpty s then "NA" else Seq.head s |> puts [] let main _ = try solve() with e -> printfn "%s" (e.ToString()) writer.Close() 0 // return an integer exit code