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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-8;
const double pi = acos(-1.0);
inline double sqr(double a) { return a * a; }
inline bool zero(double a) { return fabs(a) < eps; }
inline int sgn(double x) { return x < -eps ? -1 : x > eps; }
struct Point {
  double x, y;
  Point(double _x = 0, double _y = 0) : x(_x), y(_y) {}
  Point operator+(const Point& r) const { return Point(x + r.x, y + r.y); }
  Point operator-(const Point& r) const { return Point(x - r.x, y - r.y); }
  double operator^(const Point& r) const { return x * r.y - y * r.x; }
  Point operator*(const double& r) const { return Point(x * r, y * r); }
  Point rotate(double ag) {
    return Point(x * cos(ag) - y * sin(ag), x * sin(ag) + y * cos(ag));
  }
  void input() { scanf("%lf %lf", &x, &y); }
  double len2() { return sqr(x) + sqr(y); }
  double len() { return sqrt(len2()); }
  double dist(Point r) { return ((*this) - r).len(); }
  double ang() { return atan2(y, x); }
  void output() { printf("%lf %lf\n", x, y); }
};
double xmult(Point p1, Point p2, Point p0) { return (p1 - p0) ^ (p2 - p0); }
Point crossLine(Point a, Point b, Point c, Point d) {
  double u = xmult(b, c, a), v = xmult(a, d, b);
  return Point((c.x * v + d.x * u) / (u + v), (c.y * v + d.y * u) / (u + v));
}
double areaPolygon(int n, Point* p) {
  double area = 0.0;
  for (int i = 0; i < n; ++i) {
    area += p[i] ^ p[(i + 1) % n];
  }
  return fabs(area) / 2.0;
}
double CPIA(Point a[], Point b[], int na, int nb) {
  Point p[10], tmp[10];
  a[na] = a[0], b[nb] = b[0];
  memcpy(p, b, sizeof(Point) * (nb + 1));
  for (int i = 0; i < na && nb > 2; ++i) {
    int sflag = sgn(xmult(a[i + 1], p[0], a[i])), eflag, tn;
    for (int j = tn = 0; j < nb; ++j, sflag = eflag) {
      if (sflag >= 0) tmp[tn++] = p[j];
      eflag = sgn(xmult(a[i + 1], p[j + 1], a[i]));
      if ((sflag ^ eflag) == -2)
        tmp[tn++] = crossLine(a[i], a[i + 1], p[j], p[j + 1]);
    }
    memcpy(p, tmp, sizeof(Point) * tn);
    nb = tn, p[nb] = p[0];
  }
  if (nb < 3) return 0.0;
  return areaPolygon(nb, p);
}
int main() {
  double w, h, a;
  cin >> w >> h >> a;
  Point p[40] = {Point(-w, -h), Point(w, -h), Point(w, h), Point(-w, h)};
  Point tp[40];
  for (int i = 0; i < 4; ++i) {
    tp[i] = p[i].rotate(a / 180 * pi);
  }
  printf("%.12lf\n", CPIA(p, tp, 4, 4) / 4);
  return 0;
}