private const val SPECIAL_ATTACK_HIT_RATE = 2.0 / 3.0
private const val SPECIAL_ATTACK_NUM_EXPECTED = 1.0 / SPECIAL_ATTACK_HIT_RATE

internal fun solve(HP: Int, normal: Int, special: Int): String {
    if (normal > special){
        return (HP / normal + 1.0).toString()
    }

    fun attackUntilYouDie(currentHP: Double): Double {
        return when {
            currentHP <= 0 -> {
                0.0
            }
            currentHP <= normal -> {
                1.0
            }
            else -> {
                SPECIAL_ATTACK_NUM_EXPECTED + attackUntilYouDie(currentHP - special)
            }
        }
    }
    return attackUntilYouDie(HP.toDouble()).toString()
}

fun main(args: Array<String>) {
    var OUTPUT = ""

    val br = System.`in`.bufferedReader()
    val (HP, normal, special) = br.readLine().split(" ").map { it.toInt() }

    OUTPUT += solve(HP, normal, special)
    print(OUTPUT)
}