Problem:
Score : 400 points

Problem Statement

Takahashi has a water bottle with the shape of a rectangular prism whose base is a square of side a~\mathrm{cm} and whose height is b~\mathrm{cm}. (The thickness of the bottle can be ignored.)

We will pour x~\mathrm{cm}^3 of water into the bottle, and gradually tilt the bottle around one of the sides of the base.

When will the water be spilled? More formally, find the maximum angle in which we can tilt the bottle without spilling any water.

Constraints

All values in input are integers.

1 \leq a \leq 100

1 \leq b \leq 100

1 \leq x \leq a^2b

Input

Input is given from Standard Input in the following format:

a b x

Output

Print the maximum angle in which we can tilt the bottle without spilling any water, in degrees.
Your output will be judged as correct when the absolute or relative error from the judge's output is at most 10^{-6}.

Sample Input 1

2 2 4

Sample Output 1

45.0000000000

This bottle has a cubic shape, and it is half-full. The water gets spilled when we tilt the bottle more than 45 degrees.

Sample Input 2

12 21 10

Sample Output 2

89.7834636934

This bottle is almost empty. When the water gets spilled, the bottle is nearly horizontal.

Sample Input 3

3 1 8

Sample Output 3

4.2363947991

This bottle is almost full. When the water gets spilled, the bottle is still nearly vertical.

Solution in C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using static System.Console;
using static System.Math;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace atcoder
{
    class Program
    {
        //メイン関数
        static void Main(string[] args)
        {
            string[] reader = ReadLine().Split(' ');
            int a = int.Parse(reader[0]);
            int b = int.Parse(reader[1]);
            int x = int.Parse(reader[2]);

            int ComEmpty = a * a * b - x;
            int ComVolume = a * a * b - (b - ((2 * x) / (a * a)));
            float Ratio = ComVolume / ComEmpty;

            WriteLine(90f / Ratio);
            ReadKey();
        }




        #region 細々としたツール(関数)

        #region 標準入力
        //変数の入力
        static string scan() => ReadLine();
        static int scanInt() => int.Parse(ReadLine());

        //配列の入力
        static string[] MultiScan(char Split)
        {
            string[] N = ReadLine().Split(Split);
            return N;
        }
        static string[] MultiScan()
        {
            string[] N = ReadLine().Split(' ');
            return N;
        }

        static List<int> MultiScanInt(char Split)
        {
            string[] N = ReadLine().Split(Split);
            List<int> output = new List<int>();

            for (int i = 0; i < N.Length; i++)
            {
                output.Add(int.Parse(N[i]));
            }

            return output;
        }
        static List<int> MultiScanInt(char Split, int roop)
        { 
            string[] N = ReadLine().Split(Split);
            List<int> output = new List<int>();

            for (int i = 0; i < roop; i++)
            {
                output.Add(int.Parse(N[i]));
            }

            return output;
        }
        #endregion

        #region 数学関連
        public static int Gcd(int a, int b)
        {
            if (a < b)
                // 引数を入替えて自分を呼び出す
                return Gcd(b, a);
            while (b != 0)
            {
                var remainder = a % b;
                a = b;
                b = remainder;
            }
            return a;
        }//最大公約数
        public static int Lcm(int a, int b)
        {
            return a * b / Gcd(a, b);
        }//最小公倍数
        public static int PlusOneSigma(int x, int loop)
        {
            int output = 0;
            for (int i = 0; i < loop; i++)
            {
                output = output + x + i;
            }
            return output;
        }//１づつ加算のシグマ
        #endregion

        #endregion
    }
}