DouKaku?

open System;;

let time f =
    let start = DateTime.Now in
    let res = f () in
    let finish = DateTime.Now in
    Console.WriteLine( (finish-start) );
    res;;

let rec fib n =
    if n = 0
    then 1
    elif n = 1
    then 1
    else fib (n-1) + fib (n-2);;

let profile n = time (fun () -> fib n);;