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 INF = 1e10;
const double PI = 3.14159265358979323846;
struct Point {
  Point(double x, double y) : x(x), y(y) {}
  Point() {}
  double x, y;
};
Point operator+(const Point &a, const Point &b) {
  return Point(a.x + b.x, a.y + b.y);
}
Point operator-(const Point &a, const Point &b) {
  return Point(a.x - b.x, a.y - b.y);
}
Point operator*(const Point &a, const double b) {
  return Point(a.x * b, a.y * b);
}
Point operator*(const Point &a, const Point &b) {
  return Point(a.x * b.x - a.y * b.y, a.x * b.y + a.y * b.x);
}
Point operator/(const Point &a, const double b) {
  return Point(a.x / b, a.y / b);
}
double cross(const Point &a, const Point &b) { return a.x * b.y - a.y * b.x; }
double dot(const Point &a, const Point &b) { return a.x * b.x + a.y * b.y; }
bool operator<(const Point &a, const Point &b) {
  return make_pair(a.x, a.y) < make_pair(b.x, b.y);
}
double atan(const Point &a) { return atan2(a.y, a.x); }
double norm(const Point &a) { return dot(a, a); }
double abs(const Point &a) { return sqrt(norm(a)); }
Point rotate90(const Point &a) { return Point(-a.y, a.x); }
Point rotate(const Point &a, double angle) {
  return Point(cos(angle) * a.x - sin(angle) * a.y,
               sin(angle) * a.x + cos(angle) * a.y);
}
struct Line : vector<Point> {
  Line(Point a = Point(0, 0), Point b = Point(0, 0)) {
    this->push_back(a);
    this->push_back(b);
  }
};
struct Circle : Point {
  double r;
  Circle(Point p = Point(0, 0), double r = 0) : Point(p), r(r) {}
};
Point next(const vector<Point> &a, int x) { return a[(x + 1) % a.size()]; }
Point prev(const vector<Point> &a, int x) {
  return a[(x - 1 + a.size()) % a.size()];
}
ostream &operator<<(ostream &os, const Point &a) {
  return os << "(" << a.x << "," << a.y << ")";
}
istream &operator>>(istream &is, Point &a) { return is >> a.x >> a.y; }
int ccw(Point a, Point b, Point c) {
  b = b - a;
  c = c - a;
  if (cross(b, c) > EPS) return +1;
  if (cross(b, c) < -EPS) return -1;
  if (dot(b, c) < 0) return +2;
  if (norm(b) < norm(c)) return -2;
  return 0;
}
Point crosspoint_LL(const Line &l, const Line &m) {
  double d = cross(m[1] - m[0], l[1] - l[0]);
  if (abs(d) < EPS) throw "線分が平行です";
  return l[0] + (l[1] - l[0]) * cross(m[1] - m[0], m[1] - l[0]) * (1.0 / d);
}
double area(const vector<Point> &a) {
  double ret = 0.0;
  for (int i = 0; i < (int)(a.size()); i++) {
    ret += cross(a[i], next(a, i));
  }
  return abs(ret) * .5;
}
Point center_of_gravity(const vector<Point> &P) {
  Point p;
  for (int i = 0; i < (int)(P.size()); i++) p = p + P[i];
  return p * (1.0 / P.size());
}
vector<Point> convex_cut(const vector<Point> &P, const Line &l) {
  vector<Point> Q;
  for (int i = 0; i < P.size(); ++i) {
    Point A = P[i], B = P[(i + 1) % P.size()];
    if (ccw(l[0], l[1], A) != -1) Q.push_back(A);
    if (ccw(l[0], l[1], A) * ccw(l[0], l[1], B) < 0)
      Q.push_back(crosspoint_LL(Line(A, B), l));
  }
  return Q;
}
vector<Point> convex_hull(vector<Point> ps) {
  int n = ps.size(), k = 0;
  sort(ps.begin(), ps.end());
  vector<Point> ch(2 * n);
  for (int i = 0; i < n; ch[k++] = ps[i++])
    while (k >= 2 && ccw(ch[k - 2], ch[k - 1], ps[i]) <= 0) --k;
  for (int i = n - 2, t = k + 1; i >= 0; ch[k++] = ps[i--])
    while (k >= t && ccw(ch[k - 2], ch[k - 1], ps[i]) <= 0) --k;
  ch.resize(k - 1);
  return ch;
}
int main() {
  double W, H, A;
  cin >> W >> H >> A;
  vector<Point> P(4);
  P[0] = Point(W / 2, H / 2);
  P[1] = Point(-W / 2, H / 2);
  P[2] = Point(-W / 2, -H / 2);
  P[3] = Point(W / 2, -H / 2);
  P = convex_hull(P);
  vector<Point> Q = P;
  for (auto &a : Q) {
    a = rotate(a, A / 180 * PI);
  }
  for (int i = 0; i < (int)(4); i++) {
    Line l(Q[i], Q[(i + 1) % 4]);
    P = convex_cut(P, l);
  }
  cout << setprecision(12) << setiosflags(ios::fixed);
  cout << area(P) << endl;
}