let readString() = stdin.ReadLine()
let readStringArray() = stdin.ReadLine().Split(' ');
let readInt() = readString() |> int
let readIntArray() = readStringArray() |> Array.map (fun x -> int x)

readStringArray() |> Array.map (fun x -> x.ToUpper().[0].ToString()) |> Array.fold (fun s acc -> s + acc) ""
|> printfn "%s"