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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.text.DecimalFormat;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.TreeSet;
import java.util.stream.IntStream;

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author Andy Phan
 */
public class c {
    int[][] adj;
    int[] x, y;
    public static void main(String[] args) {
        FS in = new FS(System.in);
        PrintWriter out = new PrintWriter(System.out);
     
        new c().solve(in, out);
        
        out.close();
    }
    
    public void solve(FS in, PrintWriter out) {
        double w = in.nextInt();
        double h = in.nextInt();
        double a = in.nextInt();
        Vec[] poly = { new Vec(w/2, h/2), new Vec(-w/2, h/2), new Vec(-w/2, -h/2), new Vec(w/2, -h/2) };
        Vec[] poly2 = new Vec[4];
        for(int i = 0; i < 4; i++) poly2[i] = poly[i].rotate(Math.toRadians(a));
        for(int i = 0; i < 4; i++) {
            poly = clip(poly, new Seg(poly2[i], poly2[(i+1)%4]));
        }
        double tot = 0;
        for(int i = 0; i < poly.length; i++) tot += poly[i].add(new Vec(w, h)).cross(poly[(i+1)%poly.length].add(new Vec(w, h)));
        out.println(Math.abs(tot/2));
    }
    
    //only what is on side 1 of line will remain (positive cross product)
    static Vec[] clip(Vec[] poly, Seg line) {
        ArrayList<Vec> toReturn=new ArrayList<>();
        int nLeft=0, nRight=0, n=poly.length;
        int[] side=new int[n];
        for (int i=0; i<n; i++) {
            //old code checked cross with epsilon 1e-8
            side[i]=line.side(poly[i]);
            if (side[i]==1) nLeft++;
            if (side[i]==-1) nRight++;
        }
        if (nLeft==0) return new Vec[0];
        if (nRight==0) return poly;

        for (int i=0; i<n; i++) {
            int next=(i+1)%n;
            if (side[i]==1) toReturn.add(poly[i]);
            if (side[i]*side[next]!=1) {
                Vec intersect=line.lineIntersect(new Seg(poly[i], poly[next]));
                if (intersect!=null)
                    toReturn.add(intersect);
            }
        }

        Vec[] res=new Vec[toReturn.size()];
        for (int i=0; i<res.length; i++)
            res[i]=toReturn.get(i);
        return res;
    }

    
    static class Seg {
	Vec from, to, dir;
	
	public Seg(Vec from, Vec to) {
            this.from=from;
            this.to=to;
            dir=to.sub(from);
	}
	
	//line-line intersection
	public Vec lineIntersect(Seg o) {
            double det=o.dir.x*dir.y-dir.x*o.dir.y;
            if (Vec.eq(det, 0)) return null;
            double dist=(o.dir.x*(o.from.y-from.y)-
                    o.dir.y*(o.from.x-from.x))/det;
            return from.add(dir.scale(dist));
	}
	
	public boolean containsPoint(Vec o) {
            double distFromLine=dir.unit().cross(o.sub(from));
            if (!Vec.eq(distFromLine, 0)) return false;
            return Vec.eq(dir.mag(), from.sub(o).mag()+to.sub(o).mag());
	}
	
	//seg-seg intersection
	public Vec segIntersection(Seg o) {
            Vec intersect=lineIntersect(o);
            if(intersect == null) return null;
            return containsPoint(intersect)&&o.containsPoint(intersect)?intersect:null;
	}
	
	//returns 1 if above, 0 if on, -1 if below
	public int side(Vec o) {
            Vec oDir=o.sub(from);
            double distFromLine=dir.unit().cross(oDir);
            if (Vec.eq(distFromLine, 0))
                return 0;
            return (int)Math.signum(distFromLine);
	}
	
	public boolean intersects(Seg o) {
            return side(o.from)!=side(o.to) && o.side(from)!=o.side(to);
	}
	
	public Vec getClosestTo(Vec o) {
            double percentThere=o.sub(from).dot(dir)/dir.mag2();
            return from.add(dir.scale(Math.max(0, Math.min(1, percentThere))));
	}
	
	public Vec projectToLine(Vec o) {
            return dir.scale(o.sub(from).dot(dir)/dir.mag2()).add(from);
	}
	
	//toContain must be a point with positive x and y coordinates.
	//this method returns the shortest line segment from the x-axis to the point to the y axis
	public static Seg getShortestSegFromAxesContainingQ1Point(Vec toContain) {
            double slope=-Math.pow(toContain.y/toContain.x, 1.0/3);
            double b=toContain.y-toContain.x*slope;
            double xInt=-b/slope;
            return new Seg(new Vec(0, b), new Vec(xInt, 0));
	}
	
	public String toString() {
            return from+" -> "+to;
	}
    }
    
    static class Vec {
	static final double EPS=1e-6;
	double x, y;
	public Vec(double x, double y) {this.x=x;this.y=y;}
	public Vec add(Vec o) {return new Vec(x+o.x, y+o.y);}
	public Vec sub(Vec o) {return new Vec(x-o.x, y-o.y);}
	public Vec scale(double s) {return new Vec(x*s, y*s);}
	public double dot(Vec o) {return x*o.x+y*o.y;}
	public double cross(Vec o) {return x*o.y-y*o.x;}
	public double mag2() {return dot(this);}
	public double mag() {return Math.sqrt(mag2());}
	public Vec unit() {return scale(1/mag());}
	public Vec rot90() {return new Vec(-y, x);}
	public Vec rot270() {return new Vec(y, -x);}
	
	public Vec rotate(double theta) {
            double PI=Math.PI;
            double newX=x*Math.cos(theta)+y*Math.cos(PI/2+theta);
            double newY=x*Math.sin(theta)+y*Math.sin(PI/2+theta);
            return new Vec(newX, newY);
	}
	
	//angle between 0 and 2PI
	public double angle() {
            return (Math.atan2(y, x)+2*Math.PI)%(2*Math.PI);
	}
	
	public String toString() {
            DecimalFormat df=new DecimalFormat("#.##");
            return "("+df.format(x)+", "+df.format(y)+")";
	}
	
	static boolean eq(double a, double b) {return Math.abs(a-b)<EPS;}
	static boolean leq(double a, double b) {return a-EPS<b;}
	static boolean geq(double a, double b) {return a+EPS>b;}
	
	public boolean equals(Object oo) {
            Vec o=(Vec)oo;
            return eq(x, o.x)&&eq(y, o.y);
	}
    }

    static class FS {

        BufferedReader in;
        StringTokenizer token;

        public FS(InputStream str) {
            in = new BufferedReader(new InputStreamReader(str));
        }

        public String next() {
            if (token == null || !token.hasMoreElements()) {
                try {
                    token = new StringTokenizer(in.readLine());
                } catch (IOException ex) {
                }
                return next();
            }
            return token.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        
        public double nextDouble() {
            return Double.parseDouble(next());
        }
        
        public long nextLong() {
            return Long.parseLong(next());
        }
    }
}