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 int maxn = 1e5 + 5;
const int Mod = 1000000007;
const int INF = 0x3f3f3f3f;
const long long LL_INF = 0x3f3f3f3f3f3f3f3f;
const double e = exp(1);
const double PI = acos(-1);
const double ERR = 1e-10;
const double eps = 1e-12;
const double inf = 1e20;
const double pi = acos(-1.0);
const int maxp = 1e4 + 10;
int sgn(double x) {
  if (fabs(x) < eps) return 0;
  if (x < 0) return -1;
  return 1;
}
inline double sqr(double x) { return x * x; }
struct Point {
  double x, y;
  int id;
  Point() {}
  Point(double _x, double _y) { x = _x, y = _y; }
  void input() { scanf("%lf%lf", &x, &y); }
  void output() { cout << "x= " << x << " y= " << y << endl; }
  bool operator==(Point b) const {
    return sgn(x - b.x) == 0 && sgn(y - b.y) == 0;
  }
  bool operator<(Point b) const {
    return sgn(y - b.y) == 0 ? sgn(x - b.x) < 0 : y < b.y;
  }
  Point operator-(const Point &b) const { return Point(x - b.x, y - b.y); }
  double operator^(const Point &b) const { return x * b.y - y * b.x; }
  double operator*(const Point &b) const { return x * b.x + y * b.y; }
  double len() { return hypot(x, y); }
  double len2() { return x * x + y * y; }
  double distance(Point p) { return hypot(x - p.x, y - p.y); }
  Point operator+(const Point &b) const { return Point(x + b.x, y + b.y); }
  Point operator*(const double &k) const { return Point(x * k, y * k); }
  Point operator/(const double &k) const { return Point(x / k, y / k); }
  double rad(Point a, Point b) {
    Point p = *this;
    return fabs(atan2(fabs((a - p) ^ (b - p)), (a - p) * (b - p)));
  }
  Point trunc(double r) {
    double l = len();
    if (!sgn(l)) return *this;
    r /= l;
    return Point(x * r, y * r);
  }
  Point rotat(Point p, double angle) {
    Point v = (*this) - p;
    double c = cos(angle), s = sin(angle);
    return Point(p.x + v.x * c - v.y * s, p.y + v.x * s + v.y * c);
  }
};
struct Line {
  Point s, e;
  Line() {}
  Line(Point _s, Point _e) { s = _s, e = _e; }
  bool operator==(Line v) { return (s == v.s) && (e == v.e); }
  Line(Point p, double angle) {
    s = p;
    if (sgn(angle - pi / 2) == 0)
      e = (s + Point(0, 1));
    else
      e = (s + Point(1, tan(angle)));
  }
  Line(double a, double b, double c) {
    if (sgn(a) == 0) {
      s = Point(0, -c / b);
      e = Point(1, -c / b);
    } else if (sgn(b) == 0) {
      s = Point(-c / a, 0);
      e = Point(-c / a, 1);
    } else {
      s = Point(0, -c / b);
      e = Point(1, (-c - a) / b);
    }
  }
  Point getV() { return e - s; }
  void input() {
    s.input();
    e.input();
  }
  void adjust() {
    if (e < s) swap(s, e);
  }
  double length() { return s.distance(e); }
  double angle() {
    double k = atan2(e.y - s.y, e.x - s.x);
    if (sgn(k) < 0) k += pi;
    if (sgn(k - pi) == 0) k -= pi;
    return k;
  }
  int relation(Point p) {
    int c = sgn((p - s) ^ (e - s));
    if (c < 0)
      return 1;
    else if (c > 0)
      return 2;
    return 3;
  }
  bool pointonseg(Point p) {
    return sgn((p - s) ^ (e - s)) == 0 && sgn((p - s) * (p - e)) <= 0;
  }
  bool parallel(Line v) { return sgn((e - s) ^ (v.e - v.s)) == 0; }
  int segcrossseg(Line v) {
    int d1 = sgn((e - s) ^ (v.s - s));
    int d2 = sgn((e - s) ^ (v.e - s));
    int d3 = sgn((v.e - v.s) ^ (s - v.s));
    int d4 = sgn((v.e - v.s) ^ (e - v.s));
    if ((d1 ^ d2) == -2 && (d3 ^ d4) == -2) return 2;
    return ((d1 == 0 && sgn((v.s - s) * (v.s - e)) <= 0) ||
            (d2 == 0 && sgn((v.e - s) * (v.e - e)) <= 0) ||
            (d3 == 0 && sgn((s - v.s) * (s - v.e)) <= 0) ||
            (d4 == 0 && sgn((e - v.s) * (e - v.e)) <= 0));
  }
  Point lineprog(Point p) {
    return s + (((e - s) * ((e - s) * (p - s))) / ((e - s).len2()));
  }
  Point symmetrypoint(Point p) {
    Point q = lineprog(p);
    return Point(2.0 * q.x - p.x, 2.0 * q.y - p.y);
  }
  double dispointtoline(Point p) { return fabs((p - s) ^ (e - s)) / length(); }
  double dispointtoseg(Point p) {
    if (sgn((p - s) * (e - s)) < 0 || sgn((p - e) * (s - e)) < 0)
      return min(p.distance(s), p.distance(e));
    return dispointtoline(p);
  }
  int linecrossline(Line v) {
    if ((*this).parallel(v)) return v.relation(s) == 3;
    return 2;
  }
  Point crosspoint(Line v) {
    double a1 = (v.e - v.s) ^ (s - v.s);
    double a2 = (v.e - v.s) ^ (e - v.s);
    return Point((s.x * a2 - e.x * a1) / (a2 - a1),
                 (s.y * a2 - e.y * a1) / (a2 - a1));
  }
};
struct circle {
  Point p;
  double r;
  circle() {}
  circle(Point _p, double _r) { p = _p, r = _r; }
  circle(double x, double y, double _r) { p = Point(x, y), r = _r; }
  void input() {
    p.input();
    scanf("%Lf", &r);
  }
  void output() { printf("%.2Lf %.2Lf %.2Lf", p.x, p.y, r); }
  bool operator==(circle v) { return p == v.p && sgn(r - v.r) == 0; }
  bool operator<(circle v) const {
    return ((p < v.p) || ((p == v.p) && sgn(r - v.r) < 0));
  }
  int relationseg(Line v) {
    double dst = v.dispointtoseg(p);
    if (sgn(dst - r) < 0)
      return 2;
    else if (sgn(dst - r) == 0)
      return 1;
    return 0;
  }
  int relationline(Line v) {
    double dst = v.dispointtoline(p);
    if (sgn(dst - r) < 0)
      return 2;
    else if (sgn(dst - r) == 0)
      return 1;
    return 0;
  }
  int pointcrossline(Line v, Point &p1, Point &p2) {
    if (!(*this).relationline(v)) return 0;
    Point a = v.lineprog(p);
    double d = v.dispointtoline(p);
    d = sqrt(r * r - d * d);
    if (sgn(d) == 0) {
      p1 = a;
      p2 = a;
      return 1;
    }
    p1 = a + (v.e - v.s).trunc(d);
    p2 = a - (v.e - v.s).trunc(d);
    return 2;
  }
};
struct polygon {
  int n;
  Point p[maxp];
  Line l[maxp];
  void input(int _n) {
    n = _n;
    for (int i = 0; i < n; i++) p[i].input();
  }
  void add(Point q) { p[n++] = q; }
  void getline() {
    for (int i = 0; i < n; i++) {
      l[i] = Line(p[i], p[(i + 1) % n]);
    }
  }
  void norm() {
    Point mi = p[0];
    for (int i = 1; i < n; i++) mi = min(mi, p[i]);
    sort(p, p + n, cmp(mi));
  }
  struct cmp {
    Point p;
    cmp(const Point &p0) { p = p0; }
    bool operator()(const Point &aa, const Point &bb) {
      Point a = aa, b = bb;
      int d = sgn((a - p) ^ (b - p));
      if (d == 0) return sgn(a.distance(p) - b.distance(p)) < 0;
      return d > 0;
    }
  };
  void Graham(polygon &convex) {
    norm();
    int &top = convex.n;
    top = 0;
    if (n == 1) {
      top = 1;
      convex.p[0] = p[0];
      return;
    }
    if (n == 2) {
      top = 2;
      convex.p[0] = p[0];
      convex.p[1] = p[1];
      if (convex.p[0] == convex.p[1]) top--;
      return;
    }
    convex.p[0] = p[0];
    convex.p[1] = p[1];
    top = 2;
    for (int i = 2; i < n; i++) {
      while (top > 1 && sgn((convex.p[top - 1] - convex.p[top - 2]) ^
                            (p[i] - convex.p[top - 2])) <= 0)
        top--;
      convex.p[top++] = p[i];
    }
    if (convex.n == 2 && (convex.p[0] == convex.p[1])) convex.n--;
  }
  double getarea() {
    double sum = 0;
    for (int i = 0; i < n; i++) {
      sum += (p[i] ^ p[(i + 1) % n]);
    }
    return fabs(sum) / 2.0;
  }
} vex;
int main() {
  int w, h, a;
  scanf("%d%d%d", &w, &h, &a);
  if (a == 0 || a == 180) return 0 * printf("%.20f", 1.0 * w * h);
  double x = 0.5 * w;
  double y = 0.5 * h;
  Point p[4], p2[4];
  p[0] = Point(x, -y);
  p[1] = Point(x, y);
  p[2] = Point(-x, y);
  p[3] = Point(-x, -y);
  Line l[4], l2[4];
  double ang = 1.0 * PI * a / 180.0;
  for (int i = 0; i < 4; i++) l[i] = Line(p[i], p[(i + 1) % 4]);
  for (int i = 0; i < 4; i++) p[i] = p[i].rotat(Point(0, 0), ang);
  for (int i = 0; i < 4; i++) l2[i] = Line(p[i], p[(i + 1) % 4]);
  for (int i = 0; i < 4; i++) {
    for (int j = 0; j < 4; j++) {
      if (l[i].segcrossseg(l2[j]) != 0) {
        Point tt = l[i].crosspoint(l2[j]);
        vex.add(tt);
      }
    }
  }
  vex.norm();
  printf("%.20f\n", vex.getarea());
  return 0;
}