Problem: You are given two rectangles on a plane. The centers of both rectangles are located in the origin of coordinates (meaning the center of the rectangle's symmetry). The first rectangle's sides are parallel to the coordinate axes: the length of the side that is parallel to the Ox axis, equals w, the length of the side that is parallel to the Oy axis, equals h. The second rectangle can be obtained by rotating the first rectangle relative to the origin of coordinates by angle α.

<image>

Your task is to find the area of the region which belongs to both given rectangles. This region is shaded in the picture.

Input

The first line contains three integers w, h, α (1 ≤ w, h ≤ 106; 0 ≤ α ≤ 180). Angle α is given in degrees.

Output

In a single line print a real number — the area of the region which belongs to both given rectangles.

The answer will be considered correct if its relative or absolute error doesn't exceed 10 - 6.

Examples

Input

1 1 45


Output

0.828427125


Input

6 4 30


Output

19.668384925

Note

The second sample has been drawn on the picture above.

Solution (in JAVA):

Solution:
import java.util.List;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.ArrayList;
import java.io.BufferedReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskA {
	public void solve(int testNumber, InputReader in, PrintWriter out) {
		double w = in.nextInt();
		double h = in.nextInt();
		w /= 2;
		h /= 2;
		double angle = in.nextInt();
		angle = angle / 180 * Math.PI;

		LineGeometry.Point[] poly1 = {new LineGeometry.Point(-w, -h), new LineGeometry.Point(w, -h), new LineGeometry.Point(w, h), new LineGeometry.Point(-w, h)};
		LineGeometry.Point[] poly2 = new LineGeometry.Point[4];
		for (int i = 0; i < 4; i++) {
			poly2[i] = poly1[i].rotateCCW(angle);
		}

		for (int i = 0; i < 4; i++) {
			poly1 = LineGeometry.convexCut(poly1, poly2[i], poly2[(i + 1) % 4]);
		}

		double res = Math.abs(LineGeometry.signedArea(poly1));
		out.printf("%.10f\n", res);
	}
}

class InputReader {
	public BufferedReader reader;
	public StringTokenizer tokenizer;

	public InputReader(InputStream stream) {
		reader = new BufferedReader(new InputStreamReader(stream));
	}

	public String next() {
		while (tokenizer == null || !tokenizer.hasMoreTokens()) {
			try {
				tokenizer = new StringTokenizer(reader.readLine());
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		return tokenizer.nextToken();
	}

	public int nextInt() {
		return Integer.parseInt(next());
	}
}

class LineGeometry {

	static final double EPS = 1e-10;

	public static int sign(double a) {
		return a < -EPS ? -1 : a > EPS ? 1 : 0;
	}

	public static class Point implements Comparable<Point> {
		public double x, y;

		public Point(double x, double y) {
			this.x = x;
			this.y = y;
		}

		public Point minus(Point b) {
			return new Point(x - b.x, y - b.y);
		}

		public double cross(Point b) {
			return x * b.y - y * b.x;
		}

		public Point rotateCCW(double angle) {
			return new Point(x * Math.cos(angle) - y * Math.sin(angle), x * Math.sin(angle) + y * Math.cos(angle));
		}

		public int compareTo(Point o) {
			return Double.compare(x, o.x) != 0 ? Double.compare(x, o.x) : Double.compare(y, o.y);
		}
	}

	public static class Line {
		public double a, b, c;

		public Line(double a, double b, double c) {
			this.a = a;
			this.b = b;
			this.c = c;
		}

		public Line(Point p1, Point p2) {
			a = +(p1.y - p2.y);
			b = -(p1.x - p2.x);
			c = p1.x * p2.y - p2.x * p1.y;
		}

		public Point intersect(Line line) {
			double d = a * line.b - line.a * b;
			return sign(d) == 0 ? null : new Point(-(c * line.b - line.c * b) / d, -(a * line.c - line.a * c) / d);
		}
	}

	// -1 / 0 / 1 for clockwise / straight line / counterclockwise
	public static int orientation(Point a, Point b, Point c) {
		Point AB = b.minus(a);
		Point AC = c.minus(a);
		return sign(AB.cross(AC));
	}

	public static double signedArea(Point[] points) {
		int n = points.length;
		double area = 0;
		for (int i = 0, j = n - 1; i < n; j = i++) {
			area += (points[i].x - points[j].x) * (points[i].y + points[j].y);
		}
		return area / 2;
	}

	// cuts right part of poly
	public static Point[] convexCut(Point[] poly, Point p1, Point p2) {
		int n = poly.length;
		List<Point> res = new ArrayList<>();
		for (int i = 0, j = n - 1; i < n; j = i++) {
			int d1 = orientation(p1, p2, poly[j]);
			int d2 = orientation(p1, p2, poly[i]);
			if (d1 >= 0)
				res.add(poly[j]);
			if (d1 * d2 < 0)
				res.add(new Line(p1, p2).intersect(new Line(poly[j], poly[i])));
		}
		return res.toArray(new Point[res.size()]);
	}

	}