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.io.*;
import java.util.*;

import static java.lang.Math.*;

public class A implements Runnable {

	BufferedReader in;
	PrintWriter out;
	StringTokenizer tok;
	
	public static void main(String[] args) {
		new Thread(null, new A(), "", 64*1024*1024).start();
	}

	public void run() {
		try {
			long t1 = 0, t2 = 0, m1 = 0, m2 = 0;
			if (LOCAL) {
				t1 = System.currentTimeMillis();
				m1 = Runtime.getRuntime().freeMemory();
			}
			Locale.setDefault(Locale.US);
			if (LOCAL) {
				in = new BufferedReader(new FileReader("input.txt"));
				out = new PrintWriter("output.txt");
			} else {
				in = new BufferedReader(new InputStreamReader(System.in));
				out = new PrintWriter(System.out);
			}
			tok = new StringTokenizer("");
			solve();
			in.close();
			out.close();
			if (LOCAL) {
				t2 = System.currentTimeMillis();
				m2 = Runtime.getRuntime().freeMemory();
				System.err.println("Time = " + (t2 - t1) + " ms.");
				System.err.println("Memory = " + ((m1 - m2) / 1024) + " KB.");
			}
		} catch (Throwable e) {
			e.printStackTrace(System.err);
			throw new RuntimeException();
		}
	}

	String readString() throws IOException {
		while (!tok.hasMoreTokens()) {
			String line = in.readLine();
			if (line == null) return null;
			tok = new StringTokenizer(line);
		}
		return tok.nextToken();
	}
	
	int readInt() throws IOException {
		return Integer.parseInt(readString());
	}
	
	long readLong() throws IOException {
		return Long.parseLong(readString());
	}
	
	double readDouble() throws IOException {
		return Double.parseDouble(readString());
	}
	
	static class Mergesort {

		private Mergesort() {}

		public static void sort(int[] a) {
			mergesort(a, 0, a.length - 1);
		}

		public static void sort(long[] a) {
			mergesort(a, 0, a.length - 1);
		}

		public static void sort(double[] a) {
			mergesort(a, 0, a.length - 1);
		}

		private static final int MAGIC_VALUE = 42;

		private static void mergesort(int[] a, int leftIndex, int rightIndex) {
			if (leftIndex < rightIndex) {
				if (rightIndex - leftIndex <= MAGIC_VALUE) {
					insertionSort(a, leftIndex, rightIndex);
				} else {
					int middleIndex = (leftIndex + rightIndex) / 2;
					mergesort(a, leftIndex, middleIndex);
					mergesort(a, middleIndex + 1, rightIndex);
					merge(a, leftIndex, middleIndex, rightIndex);
				}
			}
		}

		private static void mergesort(long[] a, int leftIndex, int rightIndex) {
			if (leftIndex < rightIndex) {
				if (rightIndex - leftIndex <= MAGIC_VALUE) {
					insertionSort(a, leftIndex, rightIndex);
				} else {
					int middleIndex = (leftIndex + rightIndex) / 2;
					mergesort(a, leftIndex, middleIndex);
					mergesort(a, middleIndex + 1, rightIndex);
					merge(a, leftIndex, middleIndex, rightIndex);
				}
			}
		}

		private static void mergesort(double[] a, int leftIndex, int rightIndex) {
			if (leftIndex < rightIndex) {
				if (rightIndex - leftIndex <= MAGIC_VALUE) {
					insertionSort(a, leftIndex, rightIndex);
				} else {
					int middleIndex = (leftIndex + rightIndex) / 2;
					mergesort(a, leftIndex, middleIndex);
					mergesort(a, middleIndex + 1, rightIndex);
					merge(a, leftIndex, middleIndex, rightIndex);
				}
			}
		}

		private static void merge(int[] a, int leftIndex, int middleIndex, int rightIndex) {
			int length1 = middleIndex - leftIndex + 1;
			int length2 = rightIndex - middleIndex;
			int[] leftArray = new int[length1];
			int[] rightArray = new int[length2];
			System.arraycopy(a, leftIndex, leftArray, 0, length1);
			System.arraycopy(a, middleIndex + 1, rightArray, 0, length2);
			for (int k = leftIndex, i = 0, j = 0; k <= rightIndex; k++) {
				if (i == length1) {
					a[k] = rightArray[j++];
				} else if (j == length2) {
					a[k] = leftArray[i++];
				} else {
					a[k] = leftArray[i] <= rightArray[j] ? leftArray[i++] : rightArray[j++];
				}
			}
		}

		private static void merge(long[] a, int leftIndex, int middleIndex, int rightIndex) {
			int length1 = middleIndex - leftIndex + 1;
			int length2 = rightIndex - middleIndex;
			long[] leftArray = new long[length1];
			long[] rightArray = new long[length2];
			System.arraycopy(a, leftIndex, leftArray, 0, length1);
			System.arraycopy(a, middleIndex + 1, rightArray, 0, length2);
			for (int k = leftIndex, i = 0, j = 0; k <= rightIndex; k++) {
				if (i == length1) {
					a[k] = rightArray[j++];
				} else if (j == length2) {
					a[k] = leftArray[i++];
				} else {
					a[k] = leftArray[i] <= rightArray[j] ? leftArray[i++] : rightArray[j++];
				}
			}
		}

		private static void merge(double[] a, int leftIndex, int middleIndex, int rightIndex) {
			int length1 = middleIndex - leftIndex + 1;
			int length2 = rightIndex - middleIndex;
			double[] leftArray = new double[length1];
			double[] rightArray = new double[length2];
			System.arraycopy(a, leftIndex, leftArray, 0, length1);
			System.arraycopy(a, middleIndex + 1, rightArray, 0, length2);
			for (int k = leftIndex, i = 0, j = 0; k <= rightIndex; k++) {
				if (i == length1) {
					a[k] = rightArray[j++];
				} else if (j == length2) {
					a[k] = leftArray[i++];
				} else {
					a[k] = leftArray[i] <= rightArray[j] ? leftArray[i++] : rightArray[j++];
				}
			}
		}

		private static void insertionSort(int[] a, int leftIndex, int rightIndex) {
			for (int i = leftIndex + 1; i <= rightIndex; i++) {
				int current = a[i];
				int j = i - 1;
				while (j >= leftIndex && a[j] > current) {
					a[j + 1] = a[j];
					j--;
				}
				a[j + 1] = current;
			}
		}

		private static void insertionSort(long[] a, int leftIndex, int rightIndex) {
			for (int i = leftIndex + 1; i <= rightIndex; i++) {
				long current = a[i];
				int j = i - 1;
				while (j >= leftIndex && a[j] > current) {
					a[j + 1] = a[j];
					j--;
				}
				a[j + 1] = current;
			}
		}

		private static void insertionSort(double[] a, int leftIndex, int rightIndex) {
			for (int i = leftIndex + 1; i <= rightIndex; i++) {
				double current = a[i];
				int j = i - 1;
				while (j >= leftIndex && a[j] > current) {
					a[j + 1] = a[j];
					j--;
				}
				a[j + 1] = current;
			}
		}

	}
	
	void debug(Object... o) {
		if (LOCAL) {
			System.err.println(Arrays.deepToString(o));
		}
	}
	
	final static boolean LOCAL = System.getProperty("ONLINE_JUDGE") == null;
	
//------------------------------------------------------------------------------
	
	class Point {
		double x, y;

		public Point(double x, double y) {
			this.x = x;
			this.y = y;
		}
		
		Point rotate(double angle) {
			double nx = x * cos(angle) - y * sin(angle);
			double ny = x * sin(angle) + y * cos(angle);
			return new Point(nx, ny);
		}
	}
	
	class Line {
		double a, b, c;
		
		Line(Point A, Point B) {
			a = B.y - A.y;
			b = A.x - B.x;
			c = -A.x * a - A.y * b;
		}
		
		Point intersection(Line o) {
			double det = a * o.b - b * o.a;
			double det1 = -c * o.b + b * o.c;
			double det2 = -a * o.c + c * o.a;
			return new Point(det1 / det, det2 / det);
		}
	}
	
	void solve() throws IOException {
		double x = readDouble() / 2;
		double y = readDouble() / 2;
		if (x < y) {
			double t = x; x = y; y = t;
		}
		double alpha = readDouble();
		if (alpha > 90) {
			alpha = 180 - alpha;
		}
		if (alpha == 90) {
			out.println(4 * y * y);
			return;
		}
		if (alpha == 0) {
			out.println(4 * x * y);
			return;
		}
		alpha = toRadians(alpha);
		double beta = atan2(y, x);
		if (alpha >= beta * 2) {
			double x1 = y / tan(alpha / 2);
			double x2 = y / tan(PI / 2 - alpha / 2);
			out.println((x1 + x2) * 2*y);
			debug("4 points");
		} else {
			Point p11 = new Point(-x, y);
			Point p12 = new Point(x, y);
			Point p21 = new Point(-x, -y);
			Point p22 = new Point(x, -y);
			Point t11 = p11.rotate(alpha);
			Point t12 = p12.rotate(alpha);
			Point t21 = p21.rotate(alpha);
			Point t22 = p22.rotate(alpha);
			Line up1 = new Line(p11, p12);
			Line right1 = new Line(p12, p22);
			Line down1 = new Line(p21, p22);
			Line left1 = new Line(p11, p21);
			Line up2 = new Line(t11, t12);
			Line right2 = new Line(t12, t22);
			Line down2 = new Line(t21, t22);
			Line left2 = new Line(t11, t21);
			List<Point> list = new ArrayList<Point>();
			list.add(up1.intersection(right2));
			list.add(up1.intersection(up2));
			list.add(left1.intersection(up2));
			list.add(left1.intersection(left2));
			list.add(down1.intersection(left2));
			list.add(down1.intersection(down2));
			list.add(right1.intersection(down2));
			list.add(right1.intersection(right2));
			double S = 0;
			for (int i = 0; i < list.size(); i++) {
				int j = (i + 1) % list.size();
				Point A = list.get(i);
				Point B = list.get(j);
				S += A.x * B.y - A.y * B.x;
			}
			S = abs(0.5 * S);
			out.println(S);
			debug("8 points");
		}
	}
	
}