module EulerOne let isMultipleOf y x = x % y = 0 let isMultipleOfThree x = isMultipleOf 3 x let isMultipleOfFive x = isMultipleOf 5 x let isMultipleOfThreeOrFive x = isMultipleOfThree x || isMultipleOfFive x let ans = [1 .. 999] |> List.filter isMultipleOfThreeOrFive |> List.sum [<EntryPoint>] let main argv = printfn "%d" ans 0 // return an integer exit code