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;
int cmp(double x) {
  if (fabs(x) < eps) return 0;
  if (x > 0) return 1;
  return -1;
}
int cmp(double x, double y) { return cmp(x - y); }
inline double sqr(double x) { return x * x; }
struct point {
  double x, y;
  point() {}
  point(double a, double b) : x(a), y(b) {}
  friend point operator+(const point &a, const point &b) {
    return point(a.x + b.x, a.y + b.y);
  }
  friend point operator-(const point &a, const point &b) {
    return point(a.x - b.x, a.y - b.y);
  }
  friend bool operator==(const point &a, const point &b) {
    return cmp(a.x - b.x) == 0 && cmp(a.y - b.y) == 0;
  }
  friend bool operator<(const point &a, const point &b) {
    if (cmp(a.x - b.x) < 0) return true;
    if (cmp(a.x - b.x) > 0) return false;
    return cmp(a.y - b.y) < 0;
  }
  friend point operator*(const point &a, const double &b) {
    return point(a.x * b, a.y * b);
  }
  friend point operator*(const double &a, const point &b) {
    return point(a * b.x, a * b.y);
  }
  friend point operator/(const point &a, const double &b) {
    return point(a.x / b, a.y / b);
  }
  friend istream &operator>>(istream &fin, point &a) {
    fin >> a.x >> a.y;
    return fin;
  }
  double norm() { return sqrt(sqr(x) + sqr(y)); }
};
double det(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; }
double dist(const point &a, const point &b) { return (a - b).norm(); }
point rorate_point(const point &p, double A) {
  double tx = p.x, ty = p.y;
  return point(tx * cos(A) - ty * sin(A), tx * sin(A) + ty * cos(A));
}
struct line {
  point a, b;
  line(point x, point y) : a(x), b(y) {}
};
double dis_point_segment(const point p, const point s, const point t) {
  if (cmp(dot(p - s, t - s)) < 0) return (p - s).norm();
  if (cmp(dot(p - t, s - t)) < 0) return (p - t).norm();
  return fabs(det(s - p, t - p) / dist(s, t));
}
void PointProjLine(const point p, const point s, const point t, point &cp) {
  double r = dot((t - s), (p - s)) / dot(t - s, t - s);
  cp = s + r * (t - s);
}
bool PointOnSegment(point p, point s, point t) {
  return cmp(det(p - s, t - s)) == 0 && cmp(dot(p - s, p - t)) <= 0;
}
bool parallel(line a, line b) { return !cmp(det(a.a - a.b, b.a - b.b)); }
bool line_make_point(line a, line b, point &res) {
  if (parallel(a, b)) return false;
  double s1 = det(a.a - b.a, b.b - b.a);
  double s2 = det(a.b - b.a, b.b - b.a);
  res = (s1 * a.b - s2 * a.a) / (s1 - s2);
  return true;
}
double multiply(point sp, point ep, point op) {
  return ((sp.x - op.x) * (ep.y - op.y) - (ep.x - op.x) * (sp.y - op.y));
}
bool intersect(line u, line v) {
  return ((max(u.a.x, u.b.x) >= min(v.a.x, v.b.x)) &&
          (max(v.a.x, v.b.x) >= min(u.a.x, u.b.x)) &&
          (max(u.a.y, u.b.y) >= min(v.a.y, v.b.y)) &&
          (max(v.a.y, v.b.y) >= min(u.a.y, u.b.y)) &&
          (multiply(v.a, u.b, u.a) * multiply(u.b, v.b, u.a) >= 0) &&
          (multiply(u.a, v.b, v.a) * multiply(v.b, u.b, v.a) >= 0));
}
const int maxn = 10001;
struct polygon {
  int n;
  point a[maxn];
  double perimeter() {
    double sum = 0;
    a[n] = a[0];
    for (int i = 0; i < n; i++) sum += (a[i + 1] - a[i]).norm();
    return sum;
  }
  double area() {
    double sum = 0;
    a[n] = a[0];
    for (int i = 0; i < n; i++) sum += det(a[i + 1], a[i]);
    return sum / 2.;
  }
  int Point_In(point t) {
    int num = 0, i, d1, d2, k;
    a[n] = a[0];
    for (int i = 0; i < n; i++) {
      if (PointOnSegment(t, a[i], a[i + 1])) return 2;
      k = cmp(det(a[i + 1] - a[i], t - a[i]));
      d1 = cmp(a[i].y - t.y);
      d2 = cmp(a[i + 1].y - t.y);
      if (k > 0 && d1 <= 0 && d2 > 0) num++;
      if (k < 0 && d2 <= 0 && d1 > 0) num++;
    }
    return num & 1;
  }
};
struct polygon_convex {
  vector<point> P;
  polygon_convex(int Size = 0) { P.resize(Size); }
};
bool comp_less(const point &a, const point &b) {
  return cmp(a.x - b.x) < 0 || cmp(a.x - b.x) == 0 && cmp(a.y - b.y) < 0;
}
polygon_convex convex_hull(vector<point> a) {
  polygon_convex res(2 * a.size() + 5);
  sort(a.begin(), a.end(), comp_less);
  a.erase(unique(a.begin(), a.end()), a.end());
  int m = 0;
  for (int i = 0; i < a.size(); ++i) {
    while (m > 1 &&
           cmp(det(res.P[m - 1] - res.P[m - 2], a[i] - res.P[m - 2])) <= 0)
      --m;
    res.P[m++] = a[i];
  }
  int k = m;
  for (int i = int(a.size()) - 2; i >= 0; --i) {
    while (m > k &&
           cmp(det(res.P[m - 1] - res.P[m - 2], a[i] - res.P[m - 2])) <= 0)
      --m;
    res.P[m++] = a[i];
  }
  res.P.resize(m);
  if (a.size() > 1) res.P.resize(m - 1);
  return res;
}
int containOlogn(const polygon_convex &a, const point &b) {
  int n = a.P.size();
  point g = (a.P[0] + a.P[n / 3] + a.P[2 * n / 3]) / 3.0;
  int l = 0, r = n;
  while (l + 1 < r) {
    int mid = (l + r) / 2;
    if (cmp(det(a.P[l] - g, a.P[mid] - g)) > 0) {
      if (cmp(det(a.P[l] - g, b - g)) >= 0 && cmp(det(a.P[mid] - g, b - g)) < 0)
        r = mid;
      else
        l = mid;
    } else {
      if (cmp(det(a.P[l] - g, b - g)) < 0 && cmp(det(a.P[mid] - g, b - g)) >= 0)
        l = mid;
      else
        r = mid;
    }
  }
  r %= n;
  int z = cmp(det(a.P[r] - b, a.P[l] - b)) - 1;
  if (z == -2) return 1;
  return z;
}
bool containOn(const polygon_convex &a, const point &b) {
  int n = a.P.size();
  int sign = 0;
  for (int i = 0; i < n; ++i) {
    int x = cmp(det(a.P[i] - b, a.P[((i + 1) % n)] - b));
    if (x) {
      if (sign) {
        if (sign != x) return false;
      } else
        sign = x;
    }
  }
  return true;
}
bool inaline(line a, line b) {
  if (!parallel(a, b)) return false;
  if (cmp(det(a.a - a.b, a.a - b.a)) == 0) return true;
  return false;
}
const double INF = 10000;
inline double cross(complex<double> a, complex<double> b) {
  return (conj(a) * b).imag();
}
inline double dot(complex<double> a, complex<double> b) {
  return (conj(a) * b).real();
}
inline double satisfy(complex<double> a,
                      pair<complex<double>, complex<double> > p) {
  return cmp(cross(a - p.first, p.second - p.first)) <= 0;
}
complex<double> crosspoint(const pair<complex<double>, complex<double> > &a,
                           const pair<complex<double>, complex<double> > &b) {
  double k = cross(b.first - b.second, a.first - b.second);
  k = k / (k - cross(b.first - b.second, a.second - b.second));
  return a.first + (a.second - a.first) * k;
}
bool cmpp(const pair<complex<double>, complex<double> > &a,
          const pair<complex<double>, complex<double> > &b) {
  int res = cmp(arg(a.second - a.first) - arg(b.second - b.first));
  return res == 0 ? satisfy(a.first, b) : res < 0;
}
vector<complex<double> > HalfplaneIntersection(
    vector<pair<complex<double>, complex<double> > > v) {
  sort(v.begin(), v.end(), cmpp);
  deque<pair<complex<double>, complex<double> > > q;
  deque<complex<double> > ans;
  q.push_back(v[0]);
  for (int i = 1; i < v.size(); ++i) {
    if (cmp(arg(v[i].second - v[i].first) -
            arg(v[i - 1].second - v[i - 1].first)) == 0) {
      continue;
    }
    while (ans.size() > 0 && !satisfy(ans.back(), v[i])) {
      ans.pop_back();
      q.pop_back();
    }
    while (ans.size() > 0 && !satisfy(ans.front(), v[i])) {
      ans.pop_front();
      q.pop_front();
    }
    ans.push_back(crosspoint(q.back(), v[i]));
    q.push_back(v[i]);
  }
  while (ans.size() > 0 && !satisfy(ans.back(), q.front())) {
    ans.pop_back();
    q.pop_back();
  }
  while (ans.size() > 0 && !satisfy(ans.front(), q.back())) {
    ans.pop_front();
    q.pop_front();
  }
  ans.push_back(crosspoint(q.back(), q.front()));
  return vector<complex<double> >(ans.begin(), ans.end());
}
vector<complex<double> > convexIntersection(vector<complex<double> > v1,
                                            vector<complex<double> > v2) {
  vector<pair<complex<double>, complex<double> > > h;
  for (int i = 0; i < v1.size(); ++i)
    h.push_back(pair<complex<double>, complex<double> >(
        v1[i], v1[(i + 1) % v1.size()]));
  for (int i = 0; i < v2.size(); ++i)
    h.push_back(pair<complex<double>, complex<double> >(
        v2[i], v2[(i + 1) % v2.size()]));
  return HalfplaneIntersection(h);
}
point Pointtopoint(complex<double> p) { return point(p.real(), p.imag()); }
complex<double> pointtoPoint(point p) { return complex<double>(p.x, p.y); }
int main() {
  double w, h;
  double a;
  cin >> w >> h >> a;
  a = a * 2 * M_PI / 360;
  vector<complex<double> > c1, c2;
  complex<double> p1(w / 2, h / 2), p2(-w / 2, h / 2), p3(-w / 2, -h / 2),
      p4(w / 2, -h / 2);
  c1.push_back(p1);
  c1.push_back(p2);
  c1.push_back(p3);
  c1.push_back(p4);
  c2.push_back(pointtoPoint(rorate_point(Pointtopoint(p1), a)));
  c2.push_back(pointtoPoint(rorate_point(Pointtopoint(p2), a)));
  c2.push_back(pointtoPoint(rorate_point(Pointtopoint(p3), a)));
  c2.push_back(pointtoPoint(rorate_point(Pointtopoint(p4), a)));
  vector<complex<double> > c3 = convexIntersection(c1, c2);
  polygon pp;
  pp.n = c3.size();
  for (int i = 0; i < c3.size(); ++i) pp.a[i] = Pointtopoint(c3[i]);
  printf("%.8f", fabs(pp.area()));
}