Learning F# with Hacker Rank

gistfile1.fs

open System

//leaderboard #1
let leaderboard1 = 
    let ln = System.Console.In.ReadLine //;;

    [1..(int (ln()))] |> List.map (fun x-> ln().Split([|' '|]) |> Array.map int |> Array.reduce (+)) |> List.iter System.Console.WriteLine

//leaderboard #2
let leaderboard2 = 
      let n = Console.ReadLine() |> int
      for i = 1 to n do
        let number_string = Console.ReadLine()
        let numbers = Array.map (fun s -> int s) (number_string.Split [|' '|])
        let s = Array.sum numbers
        printfn "%d" s

//leaderboard #3
let leaderboard3 = 
    let count = stdin.ReadLine() |> int
    Seq.init count (fun i -> stdin.ReadLine().Split() |> Seq.map int)
    |> Seq.map Seq.sum
    |> Seq.iter (fun x -> printfn "%d" x)

//my try ( could not figure out how to pipeline this :( )
//pipeline attempt
//  [1..lines] |> Seq.iter ( printf "%i\n" (Console.ReadLine().Split() |> Seq.map int |> Seq.sum) )
let mySolution = 
    let lines = Console.ReadLine() |> int

    for i = 1 to lines do
        //my first iteration
        //let numbers = Console.ReadLine().Split[|' '|] |> Seq.map int
        //printf "%i\n" ((numbers |> Seq.nth 0) + (numbers |> Seq.nth 1))
        
        //second iteration
        printfn "%i" (Console.ReadLine().Split() |> Seq.map int |> Seq.sum)


[<EntryPoint>]
let main argv = 
    mySolution

    0 // return an integer exit code