open System

​

module Array2D =

    let sum (arr:int[,]) =

        let sum = ref 0

        arr |> Array2D.iter( fun x -> sum := !sum + x)

        !sum 

​

let readInput() =

    let str = Console.ReadLine()

    str.Split [|' '|]

    |> Array.map int

let setArray2D (arr: int[,]) i vals = arr.[i, *] <- vals

​

let readArray() =

    let res = Array2D.zeroCreate 6 6

​

    for i in 0 .. 5 do 

        let vals  = readInput()

        setArray2D  res i vals

    res

​

let hourglass row col (arr:int[,]) = 

    let m = arr |> Array2D.length1

    let n = arr |> Array2D.length2

    match row, col with

        |  r, c when r <= (m - 3) && c <= ( n - 3) -> 

            //result Array

            let res = Array2D.zeroCreate<int> 3 3

            //copy to 3x3 subArray

            Array2D.blit arr row col res 0 0 3 3

            //Transform as "hourglass"

            res.[1,0] <- 0

            res.[1,2] <- 0

            res |> Array2D.sum |> Some

        | _ -> None

​

let maxHg (arr:int[,]) =

    let m = arr |> Array2D.length1

    let n = arr |> Array2D.length2

    [|

        for r in 0..(m - 1) do

            for c in 0..(n - 1) do

                yield hourglass r c arr

    |]

    |> Array.choose id

    |> Array.max

​

let solution = readArray >> maxHg

​

[<EntryPoint>]

let main argv =

    solution()

    |> printfn "%d"

    |> ignore

    0

​