defmodule Main do
  def main do
    d = IO.read(:line) |> String.trim |> String.to_integer;
    [a, b] = IO.read(:line) |> String.trim |> String.split(" ") |> Enum.map(&String.to_integer/1)
    x_list = Enum.to_list(0..d+1);
    ans = x_list |> Enum.map &(&1 * a + (d - &1) * b);
    Enum.max(ans) |> IO.puts;
  end
end