let solve n p =
    let p2 = 1.0 -. p in
    let s = Array.init (n+1) (fun i -> 1.0) in
    let ans = ref 0.0 in
    for i = 2 to n do
        ans :=  !ans +. s.(i);
        let j = ref (i*2) in
        while !j <= n do
            s.(!j) <- s.(!j) *. p2;
            j := !j + i;
        done
    done;
    !ans


let () = Scanf.scanf "%d %f" (fun n p ->
    let ans = solve n p in
    Printf.printf "%f\n" ans)