fun main(args: Array<String>) {
    val (a, b, x) = readLine()?.split(" ")?.map(String::toDouble) ?: return
    val h = x / (a * a)
    if (h > b / 2) {
        val r = (b - h) * a * a
        val c = 2 * r / (a * a)
        val d = Math.atan(c / a) * 180 / Math.PI
        println(String.format("%.10f", d))
    } else {
        val c = 2 * x / (a * b)
        val d = Math.atan(b / c) * 180 / Math.PI
        println(String.format("%.10f", d))
    }
}
