fun main(args: Array<String>) {
    val (a, b, x) = readLine()!!.split(' ').map { it.toDouble() }
    val h = x / (a * a)
    val thr = a * a * b / 2
    if (x > thr) {
        val diff = b - h
        println(Math.atan((diff * 2) / a) * 180 / Math.PI)
    } else {
        val y = x / b / a * 2
        println(90 - Math.atan(y / b) * 180 / Math.PI)
    }
}