fun main(args : Array<String>) {
    val (a, b, x) = readLine()!!.split(" ").map { it.toDouble() }
    val h = x / (a*a)

    if (h > b/2.0) {
        val r = Math.atan(2*(a*a*b-x)/(a*a*a))
        println(Math.toDegrees(r))
    } else {
        val r = Math.atan(a*b*b/(2*x))
        println(Math.toDegrees(r))
    }
}