let rec sum x n =
  if n = 0 then 0
  else
    let flx = floor x in
    let x1 = x -. flx in
    let x2 = x1 *. 10.0 in
    let m = int_of_float (floor x2) in
    m + sum x2 (n - 1)

let _ =
  try
    while true do
      let a, b, n = Scanf.scanf "%d %d %d\n" (fun x y z -> (x, y, z)) in
      Printf.printf "%d\n" (sum ((float_of_int a) /. (float_of_int b)) n);
    done
  with
    End_of_file -> ()