H, A, D = gets.split.map(&:to_i)

dp = Array.new(H + 1, Float::INFINITY)
dp[0] = 0.0

1.upto(H) do |h|
  if h - A >= 0
    dp[h] = dp[h - A] + 1.0
  else
    dp[h] = dp[0] + 1.0
  end

  if h - D >= 0
    dp[h] = dp[h - D] + 1.5 if dp[h] > dp[h - D] + 1.5
  else
    dp[h] = dp[0] + 1.5 if dp[h] > dp[0] + 1.5
  end
end

puts dp[H]