let R () = stdin.ReadLine()

let N, M = 
    let t = R().Split() |> Array.map int
    t.[0], t.[1]
let A = Array.init N (fun _ -> R())

let countWhite (line:string) =
    line.ToCharArray()
    |> Array.where(fun x -> x = 'W')
    |> Array.length
    
let ans = A |> Array.sumBy(countWhite)

ans |> printfn "%i"