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;
namespace std {
bool operator<(const complex<double>& a, const complex<double>& b) {
  return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b);
}
}  // namespace std
double inline LE(double a, double b) { return a - 1e-9 < b; }
double inline GE(double a, double b) { return a - 1e-9 > b; }
double inline EQ(double a, double b) { return fabs(a - b) < 1e-9; }
double cross(const complex<double>& a, const complex<double>& b) {
  return imag(conj(a) * b);
}
enum { OUT, ON, IN };
int convex_contains(const vector<complex<double> >& P,
                    const complex<double>& p) {
  const int n = P.size();
  complex<double> g = (P[0] + P[n / 3] + P[2 * n / 3]) / 3.0;
  int a = 0, b = n;
  while (a + 1 < b) {
    int c = (a + b) / 2;
    if (cross(P[a] - g, P[c] - g) > 0) {
      if (cross(P[a] - g, p - g) > 0 && cross(P[c] - g, p - g) < 0)
        b = c;
      else
        a = c;
    } else {
      if (cross(P[a] - g, p - g) < 0 && cross(P[c] - g, p - g) > 0)
        a = c;
      else
        b = c;
    }
  }
  b %= n;
  if (cross(P[a] - p, P[b] - p) < 0) return 0;
  if (cross(P[a] - p, P[b] - p) > 0) return 2;
  return 1;
}
bool intersect_1pt(const complex<double>& a, const complex<double>& b,
                   const complex<double>& c, const complex<double>& d,
                   complex<double>& r) {
  double D = cross(b - a, d - c);
  if (EQ(D, 0)) return false;
  double t = cross(c - a, d - c) / D;
  double s = -cross(a - c, b - a) / D;
  r = a + t * (b - a);
  return GE(t, 0) && LE(t, 1) && GE(s, 0) && LE(s, 1);
}
vector<complex<double> > convex_intersect(const vector<complex<double> >& P,
                                          const vector<complex<double> >& Q) {
  const int n = P.size(), m = Q.size();
  int a = 0, b = 0, aa = 0, ba = 0;
  enum { Pin, Qin, Unknown } in = Unknown;
  vector<complex<double> > R;
  do {
    int a1 = (a + n - 1) % n, b1 = (b + m - 1) % m;
    double C = cross(P[a] - P[a1], Q[b] - Q[b1]);
    double A = cross(P[a1] - Q[b], P[a] - Q[b]);
    double B = cross(Q[b1] - P[a], Q[b] - P[a]);
    complex<double> r;
    if (intersect_1pt(P[a1], P[a], Q[b1], Q[b], r)) {
      if (in == Unknown) aa = ba = 0;
      R.push_back(r);
      in = B > 0 ? Pin : A > 0 ? Qin : in;
    }
    if (C == 0 && B == 0 && A == 0) {
      if (in == Pin) {
        b = (b + 1) % m;
        ++ba;
      } else {
        a = (a + 1) % m;
        ++aa;
      }
    } else if (C >= 0) {
      if (A > 0) {
        if (in == Pin) R.push_back(P[a]);
        a = (a + 1) % n;
        ++aa;
      } else {
        if (in == Qin) R.push_back(Q[b]);
        b = (b + 1) % m;
        ++ba;
      }
    } else {
      if (B > 0) {
        if (in == Qin) R.push_back(Q[b]);
        b = (b + 1) % m;
        ++ba;
      } else {
        if (in == Pin) R.push_back(P[a]);
        a = (a + 1) % n;
        ++aa;
      }
    }
  } while ((aa < n || ba < m) && aa < 2 * n && ba < 2 * m);
  if (in == Unknown) {
    if (convex_contains(Q, P[0])) return P;
    if (convex_contains(P, Q[0])) return Q;
  }
  return R;
}
void rotate(double& x, double& y, double angle) {
  double tx = x * cos(angle) - y * sin(angle);
  double ty = x * sin(angle) + y * cos(angle);
  x = tx;
  y = ty;
}
double area(const vector<complex<double> >& P) {
  double A = 0;
  for (int i = 0; i < P.size(); ++i) A += cross(P[i], P[(i + 1) % P.size()]);
  return abs(A) / 2;
}
int main() {
  int w, h, alpha;
  cin >> w >> h >> alpha;
  vector<complex<double> > p1, p2;
  p1.push_back(complex<double>(w / 2., h / 2.));
  p1.push_back(complex<double>(-w / 2., h / 2.));
  p1.push_back(complex<double>(-w / 2., -h / 2.));
  p1.push_back(complex<double>(w / 2., -h / 2.));
  for (int i = 0; i < 4; i++) {
    double x = p1[i].real(), y = imag(p1[i]);
    rotate(x, y, alpha * acos(-1.) / 180.);
    p2.push_back(complex<double>(x, y));
  }
  vector<complex<double> > p3 = convex_intersect(p1, p2);
  double ans = area(p3);
  cout.precision(7);
  cout.flags(ios::fixed);
  cout << ans << endl;
}