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-9;
const double pi = acos(-1);
struct point {
  double x, y;
  point(double x = 0, double y = 0) : x(x), y(y) {}
  bool operator<(const point& o) const {
    if (fabs(x - o.x) < eps) return y < o.y;
    return x < o.x;
  }
  point rotate(double alpha) {
    alpha = alpha * pi / 180;
    return point(x * cos(alpha) - y * sin(alpha),
                 x * sin(alpha) + y * cos(alpha));
  }
  bool operator==(const point& o) const {
    return fabs(x - o.x) < eps && fabs(y - o.y) < eps;
  }
};
bool onSegment(point p, point q, point r) {
  if (q.x <= max(p.x, r.x) && q.x >= min(p.x, r.x) && q.y <= max(p.y, r.y) &&
      q.y >= min(p.y, r.y))
    return true;
  return false;
}
int orientation(point p, point q, point r) {
  double val = (q.y - p.y) * (r.x - q.x) - (q.x - p.x) * (r.y - q.y);
  if (fabs(val) < eps) return 0;
  return (val > eps) ? 1 : 2;
}
point lineLineIntersection(point A, point B, point C, point D) {
  double a1 = B.y - A.y;
  double b1 = A.x - B.x;
  double c1 = a1 * (A.x) + b1 * (A.y);
  double a2 = D.y - C.y;
  double b2 = C.x - D.x;
  double c2 = a2 * (C.x) + b2 * (C.y);
  double determinant = a1 * b2 - a2 * b1;
  if (determinant == 0) {
    puts("FAILED");
    return point(0, 0);
  } else {
    double x = (b2 * c1 - b1 * c2) / determinant;
    double y = (a1 * c2 - a2 * c1) / determinant;
    return point(x, y);
  }
}
bool intersect(point p1, point q1, point p2, point q2, point& res) {
  int o1 = orientation(p1, q1, p2);
  int o2 = orientation(p1, q1, q2);
  int o3 = orientation(p2, q2, p1);
  int o4 = orientation(p2, q2, q1);
  if (o1 != o2 && o3 != o4) {
    res = lineLineIntersection(p1, q1, p2, q2);
    return true;
  }
  if (o1 == 0 && onSegment(p1, p2, q1)) {
    res = p2;
    return true;
  }
  if (o2 == 0 && onSegment(p1, q2, q1)) {
    res = q2;
    return true;
  }
  if (o3 == 0 && onSegment(p2, p1, q2)) {
    res = p1;
    return true;
  }
  if (o4 == 0 && onSegment(p2, q1, q2)) {
    res = q1;
    return true;
  }
  return false;
}
bool same(vector<point> a, vector<point> b) {
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  return a == b;
}
double ccw(point O, point A, point B) {
  return (A.x - O.x) * (B.y - O.y) - (A.y - O.y) * (B.x - O.x);
}
vector<point> convex_hull(vector<point> pts) {
  vector<point> up, lo;
  sort(pts.begin(), pts.end());
  for (int i = 0; i < pts.size(); i++) {
    while (lo.size() >= 2 &&
           ccw(lo[lo.size() - 2], lo[lo.size() - 1], pts[i]) <= eps)
      lo.pop_back();
    lo.push_back(pts[i]);
  }
  for (int i = pts.size() - 1; i >= 0; i--) {
    while (up.size() >= 2 &&
           ccw(up[up.size() - 2], up[up.size() - 1], pts[i]) <= eps)
      up.pop_back();
    up.push_back(pts[i]);
  }
  up.pop_back();
  lo.pop_back();
  vector<point> ch;
  for (auto x : lo) ch.push_back(x);
  for (auto x : up) ch.push_back(x);
  ch.push_back(ch[0]);
  return ch;
}
int main() {
  double h, w, alpha;
  cin >> w >> h >> alpha;
  vector<point> rec;
  rec.push_back(point(w / 2, h / 2));
  rec.push_back(point(-w / 2, h / 2));
  rec.push_back(point(-w / 2, -h / 2));
  rec.push_back(point(w / 2, -h / 2));
  rec.push_back(rec[0]);
  vector<point> rot;
  for (auto p : rec) rot.push_back(p.rotate(alpha));
  if (same(rec, rot)) {
    cout << fixed << setprecision(8) << w * h << endl;
    return 0;
  }
  vector<point> all;
  for (int i = 0; i < rec.size() - 1; i++) {
    for (int j = 0; j < rot.size() - 1; j++) {
      point p;
      bool can = intersect(rec[i], rec[i + 1], rot[j], rot[j + 1], p);
      if (can) all.push_back(p);
    }
  }
  all = convex_hull(all);
  double area = 0.0;
  for (int i = 0; i < all.size() - 1; i++) {
    area += (all[i].x + all[i + 1].x) * (all[i].y - all[i + 1].y);
  }
  cout << fixed << setprecision(8) << fabs(area / 2.0) << endl;
}