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;
int DEBUG = 0;
const double eps = 1.0e-10;
const double pi = 3.141592653589793238462;
double dMin(double a, double b) { return (a < b ? a : b); }
double dMax(double a, double b) { return (a > b ? a : b); }
double dAbs(double a) { return (a >= 0 ? a : -a); }
struct PT {
  double angle;
  double x;
  double y;
  PT() {}
  PT(double angle_, double x_, double y_) : angle(angle_), x(x_), y(y_) {}
  bool operator<(const PT &b) const {
    if (this->angle < b.angle) return true;
    if (this->angle > b.angle) return false;
    if (this->x < b.x) return true;
    if (this->x > b.x) return false;
    if (this->y < b.y) return true;
    if (this->y > b.y) return false;
    return false;
  }
};
double point_distance(double x1, double y1, double x2, double y2) {
  return sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));
}
bool point_on_segment(double x, double y, double x1, double y1, double x2,
                      double y2) {
  if (dAbs(point_distance(x, y, x1, y1) + point_distance(x, y, x2, y2) -
           point_distance(x1, y1, x2, y2)) < eps)
    return true;
  return false;
}
bool segment_intersect(double x1, double y1, double x2, double y2, double x3,
                       double y3, double x4, double y4, double &x, double &y) {
  x = 0;
  y = 0;
  double dx21 = x2 - x1;
  double dx31 = x3 - x1;
  double dx43 = x4 - x3;
  double dy21 = y2 - y1;
  double dy31 = y3 - y1;
  double dy43 = y4 - y3;
  double A = dy21 * dx43 - dy43 * dx21;
  if (dAbs(A) < eps) {
    return false;
  }
  x = (dy21 * dx43 * x1 - dy43 * dx21 * x3 + dy31 * dx21 * dx43) / (A);
  y = (dx21 * dy43 * y1 - dx43 * dy21 * y3 + dx31 * dy21 * dy43) / (-A);
  if (point_on_segment(x, y, x1, y1, x2, y2) &&
      point_on_segment(x, y, x3, y3, x4, y4))
    return true;
  return false;
}
double shoelace_area(double x1, double y1, double x2, double y2, double x3,
                     double y3) {
  return dAbs(0.5 *
              (x1 * y2 + x2 * y3 + x3 * y1 - x2 * y1 - x3 * y2 + x1 * y3));
}
void rotate(double x0, double y0, double theta, double &x, double &y) {
  double co = cos(theta);
  double si = sin(theta);
  x = x0 * co - y0 * si;
  y = x0 * si + y0 * co;
}
int main(int argc, char **argv) {
  DEBUG = (argc >= 2) ? atoi(argv[1]) : 0;
  double w, h, alpha;
  int ialpha;
  cin >> w >> h >> ialpha;
  alpha = ialpha;
  if (ialpha == 0 || ialpha == 180) {
    printf("%.10lf\n", w * h);
    return 0;
  }
  if (alpha == 90) {
    printf("%.10lf\n", (min(w, h) * min(w, h)));
    return 0;
  }
  double xo[4], yo[4], xr[4], yr[4];
  xo[0] = w / 2.0;
  yo[0] = h / 2.0;
  xo[1] = -xo[0];
  yo[1] = yo[0];
  xo[2] = -xo[0];
  yo[2] = -yo[0];
  xo[3] = xo[0];
  yo[3] = -yo[0];
  double alpha_rad = alpha / 180.0 * pi;
  for (int i = 0; i < 4; i++) {
    rotate(xo[i], yo[i], alpha_rad, xr[i], yr[i]);
  }
  vector<PT> vec;
  double x, y;
  for (int i1 = 0; i1 < 4; i1++) {
    int i2 = (i1 + 1) % 4;
    for (int j1 = 0; j1 < 4; j1++) {
      int j2 = (j1 + 1) % 4;
      if (segment_intersect(xo[i1], yo[i1], xo[i2], yo[i2], xr[j1], yr[j1],
                            xr[j2], yr[j2], x, y)) {
        double angle = atan2(y, x);
        vec.push_back(PT(angle, x, y));
        if (DEBUG) {
          printf(
              "%.2f %.2f | %.2f %.2f %.2f %.2f | %.2f %.2f %.2f %.2f,  "
              "vec.size()= %d\n",
              x, y, xo[i1], yo[i1], xo[i2], yo[i2], xr[j1], yr[j1], xr[j2],
              yr[j2], vec.size());
        }
      }
    }
  }
  sort(vec.begin(), vec.end());
  double area = 0.0;
  for (int i = 0; i < int(vec.size()); i++) {
    int i2 = (i + 1) % vec.size();
    area += shoelace_area(0, 0, vec[i].x, vec[i].y, vec[i2].x, vec[i2].y);
  }
  printf("%.10lf\n", area);
  return 0;
}