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, PI = acos(-1);
inline bool eq(double a, double b) { return abs(b - a) < EPS; }
enum { OUT, ON, IN };
namespace Geometory {
struct Point {
  double x, y;
  Point(){};
  Point(double x, double y) : x(x), y(y){};
  Point operator+(const Point &b) const { return Point(x + b.x, y + b.y); }
  Point operator-(const Point &b) const { return Point(x - b.x, y - b.y); }
  Point operator*(const double b) const { return Point(x * b, y * b); }
  Point operator*(const Point &b) const {
    return Point(x * b.x - y * b.y, x * b.y + y * b.x);
  }
  Point operator/(const double b) const { return Point(x / b, y / b); }
  bool operator<(const Point &b) const { return x != b.x ? x < b.x : y < b.y; }
  bool operator==(const Point &b) const { return eq(x, b.x) && eq(y, b.y); }
  double norm() { return x * x + y * y; }
  double arg() { return atan2(x, y); }
  double abs() { return sqrt(norm()); }
  Point rotate(double theta) {
    return Point(cos(theta) * x - sin(theta) * y,
                 sin(theta) * x + cos(theta) * y);
  }
  Point rotate90() { return Point(-y, x); }
  friend ostream &operator<<(ostream &os, Point &p) {
    return os << "(" << p.x << "," << p.y << ")";
  }
  friend istream &operator>>(istream &is, Point &a) { return is >> a.x >> a.y; }
};
struct Line {
  Point a, b;
  Line(){};
  Line(Point a, Point b) : a(a), b(b){};
  friend ostream &operator<<(ostream &os, Line &p) {
    return os << "(" << p.a.x << "," << p.a.y << ") to (" << p.b.x << ","
              << p.b.y << ")";
  }
  friend istream &operator>>(istream &is, Line &a) {
    return is >> a.a.x >> a.a.y >> a.b.x >> a.b.y;
  }
};
struct Segment {
  Point a, b;
  Segment(){};
  Segment(Point a, Point b) : a(a), b(b){};
  friend ostream &operator<<(ostream &os, Segment &p) {
    return os << "(" << p.a.x << "," << p.a.y << ") to (" << p.b.x << ","
              << p.b.y << ")";
  }
  friend istream &operator>>(istream &is, Segment &a) {
    return is >> a.a.x >> a.a.y >> a.b.x >> a.b.y;
  }
};
struct Circle {
  Point p;
  double r;
  Circle(){};
  Circle(Point p, double r) : p(p), r(r){};
};
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; }
int ccw(const 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 (b.norm() < c.norm()) return -2;
  return 0;
}
Point Projection(const Line &l, const Point &p) {
  double t = dot(p - l.a, l.a - l.b) / (l.a - l.b).norm();
  return l.a + (l.a - l.b) * t;
}
Point Projection(const Segment &l, const Point &p) {
  double t = dot(p - l.a, l.a - l.b) / (l.a - l.b).norm();
  return l.a + (l.a - l.b) * t;
}
Point Reflection(const Line &l, const Point &p) {
  return p + (Projection(l, p) - p) * 2.0;
}
double Distance(const Line &l, const Point &p) {
  return (p - Projection(l, p)).abs();
}
bool Intersect(const Line &l, const Line &m) {
  return abs(cross(l.b - l.a, m.b - m.a)) > EPS ||
         abs(cross(l.b - l.a, m.b - l.a)) < EPS;
}
bool Intersect(const Line &l, const Segment &s) {
  return cross(l.b - l.a, s.a - l.a) * cross(l.b - l.a, s.b - l.a) < EPS;
}
bool Intersect(const Line &l, const Point &p) {
  return abs(ccw(l.a, l.b, p)) != -1;
}
bool Intersect(const Segment &s, const Segment &t) {
  return ccw(s.a, s.b, t.a) * ccw(s.a, s.b, t.b) <= 0 &&
         ccw(t.a, t.b, s.a) * ccw(t.a, t.b, s.b) <= 0;
}
bool Intersect(const Segment &s, const Point &p) {
  return ccw(s.a, s.b, p) == 0;
}
bool Intersect(const Circle &c, const Line &l) {
  return Distance(l, c.p) <= c.r + EPS;
}
bool Intersect(const Circle &c, const Point &p) {
  return abs((p - c.p).abs() - c.r) < EPS;
}
int Intersect(const Circle &c, const Segment &l) {
  if ((Projection(l, c.p) - c.p).norm() - c.r * c.r > EPS) return 0;
  const double d1 = (c.p - l.a).abs(), d2 = (c.p - l.b).abs();
  if (d1 < c.r + EPS && d2 < c.r + EPS) return 0;
  if (d1 < c.r - EPS && d2 > c.r + EPS || d1 > c.r + EPS && d2 < c.r - EPS)
    return 1;
  const Point h = Projection(l, c.p);
  if (dot(l.a - h, l.b - h) < 0) return 2;
  return 0;
}
bool Intersect(const Circle &a, const Circle &b) {
  return ((a.p - b.p).norm() - (a.r + b.r) * (a.r + b.r) < EPS) &&
         ((a.p - b.p).norm() - (a.r - b.r) * (a.r - b.r) > -EPS);
}
double Distance(const Segment &s, const Point &p) {
  Point r = Projection(s, p);
  if (Intersect(s, r)) return (r - p).abs();
  return min((s.a - p).abs(), (s.b - p).abs());
}
double Distance(const Segment &a, const Segment &b) {
  if (Intersect(a, b)) return 0;
  return min(min(Distance(a, b.a), Distance(a, b.b)),
             min(Distance(b, a.a), Distance(b, a.b)));
}
double Distance(const Line &l, const Line &m) {
  return Intersect(l, m) ? 0 : Distance(l, m.a);
}
double Distance(const Line &l, const Segment &s) {
  if (Intersect(l, s)) return 0;
  return min(Distance(l, s.a), Distance(l, s.b));
}
double Distance(const Point &a, const Point &b) { return (a - b).abs(); }
Point Crosspoint(const Segment &l, const Segment &m) {
  double A = cross(l.b - l.a, m.b - m.a);
  double B = cross(l.b - l.a, l.b - m.a);
  if (abs(A) < EPS && abs(B) < EPS) return m.a;
  return m.a + (m.b - m.a) * B / A;
}
pair<Point, Point> Crosspoint(const Circle &c, const Line l) {
  Point hp = Projection(l, c.p), h = hp - c.p;
  const double d2 = h.norm();
  Point v = (l.b - l.a) * sqrt(c.r * c.r - d2) / (l.b - l.a).abs();
  return pair<Point, Point>(hp - v, hp + v);
}
pair<Point, Point> Crosspoint(const Circle &c, const Segment &l) {
  Line aa = Line(l.a, l.b);
  if (Intersect(c, l) == 2) return Crosspoint(c, aa);
  pair<Point, Point> ret = Crosspoint(c, aa);
  if (dot(l.a - ret.first, l.b - ret.first) < 0)
    ret.second = ret.first;
  else
    ret.first = ret.second;
  return ret;
}
pair<Point, Point> Crosspoint(const Circle &c1, const Circle &c2) {
  double d = (c1.p - c2.p).abs();
  double s = (c1.r + c2.r + d) / 2;
  double S = sqrt(s * (s - c1.r) * (s - c2.r) * (s - d));
  double h = 2 * S / d;
  Point v = (c2.p - c1.p) / (c2.p - c1.p).abs();
  double m = sqrt(c1.r * c1.r - h * h);
  return pair<Point, Point>(c1.p + v * m + Point(0, 1) * h * v,
                            c1.p + v * m - Point(0, 1) * h * v);
}
bool parallel(const Line &a, const Line &b) {
  return abs(cross(a.b - a.a, b.b - b.a)) < EPS;
}
bool orthogonal(const Line &a, const Line &b) {
  return abs(dot(a.a - a.b, b.a - b.b)) < EPS;
}
int Contains(const vector<Point> &Q, const Point &p) {
  bool in = false;
  for (int i = 0; i < Q.size(); i++) {
    Point a = Q[i] - p, b = Q[(i + 1) % Q.size()] - p;
    if (a.y > b.y) swap(a, b);
    if (a.y <= 0 && 0 < b.y && cross(a, b) < 0) in = !in;
    if (cross(a, b) == 0 && dot(a, b) <= 0) return ON;
  }
  return in ? IN : OUT;
}
bool Contains(const Circle &c, const Point &p) {
  return (c.p - p).abs() < c.r + EPS;
}
double Area2(const vector<Point> &p) {
  double A = 0;
  for (int i = 0; i < p.size(); ++i) {
    A += cross(p[i], p[(i + 1) % p.size()]);
  }
  return A;
}
bool IsConvex(const vector<Point> &p) {
  for (int i = 0; i < p.size(); i++) {
    if (ccw(p[(i + p.size() - 1) % p.size()], p[i], p[(i + 1) % p.size()]) ==
        -1)
      return false;
  }
  return true;
}
vector<Point> Convex_Hull(vector<Point> &p) {
  int n = p.size(), k = 0;
  if (n >= 3) {
    sort(p.begin(), p.end());
    vector<Point> ch(2 * n);
    for (int i = 0; i < n; ch[k++] = p[i++]) {
      while (k >= 2 && cross(ch[k - 1] - ch[k - 2], p[i] - ch[k - 1]) < 0) --k;
    }
    for (int i = n - 2, t = k + 1; i >= 0; ch[k++] = p[i--]) {
      while (k >= t && cross(ch[k - 1] - ch[k - 2], p[i] - ch[k - 1]) < 0) --k;
    }
    ch.resize(k - 1);
    return ch;
  } else {
    return p;
  }
}
double Convex_Diameter(vector<Point> &p) {
  int n = p.size();
  int is = 0, js = 0;
  for (int i = 1; i < n; i++) {
    if (p[i].y > p[is].y) is = i;
    if (p[i].y < p[js].y) js = i;
  }
  double maxdis = (p[is] - p[js]).norm();
  int maxi, maxj, i, j;
  i = maxi = is;
  j = maxj = js;
  do {
    if (cross(p[(i + 1) % p.size()] - p[i], p[(j + 1) % p.size()] - p[j]) >=
        0) {
      j = (j + 1) % n;
    } else {
      i = (i + 1) % n;
    }
    if ((p[i] - p[j]).norm() > maxdis) {
      maxdis = (p[i] - p[j]).norm();
      maxi = i;
      maxj = j;
    }
  } while (i != is || j != js);
  return maxdis;
}
};  // namespace Geometory
using namespace Geometory;
int main() {
  double W, H, A;
  cin >> W >> H >> A;
  cout << fixed << setprecision(10);
  if (eq(A, 0) || eq(A, 180)) {
    cout << W * H << endl;
    return (0);
  }
  if (eq(A, 90)) {
    cout << min(W, H) * min(W, H) << endl;
    return (0);
  }
  if (A > 90) A = 180 - A;
  A = acos(-1) * A / 180.0;
  vector<Point> s;
  s.push_back(Point(W / 2, H / 2));
  s.push_back(Point(W / 2, -H / 2));
  s.push_back(Point(-W / 2, -H / 2));
  s.push_back(Point(-W / 2, H / 2));
  vector<Point> t = s;
  for (auto &p : t) {
    Point tt = p;
    p.x = tt.x * cos(A) - tt.y * sin(A);
    p.y = tt.x * sin(A) + tt.y * cos(A);
  }
  vector<Point> qs;
  for (int i = 0; i < s.size(); i++) {
    for (int j = 0; j < t.size(); j++) {
      if (Intersect(Segment(s[i], s[(i + 1) % s.size()]),
                    Segment(t[j], t[(j + 1) % t.size()]))) {
        qs.push_back(Crosspoint(Segment(s[i], s[(i + 1) % s.size()]),
                                Segment(t[j], t[(j + 1) % t.size()])));
      }
    }
  }
  qs = Convex_Hull(qs);
  cout << Area2(qs) * 0.5 << endl;
}