Scanf.scanf "%d %d" (fun n m ->
    let a = Array.init n (fun _ -> Scanf.scanf " %s" (fun a -> a)) in
    Array.fold_left (fun acc v ->
        let rec loop i acc =
            if i = m then acc else loop (i + 1) (if v.[i] = 'W' then acc + 1 else acc)
        in
        loop 0 acc
    ) 0 a |> Printf.printf "%d\n"
)