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>
#pragma comment(linker, "/STACK:102400000,102400000")
template <class T>
inline void gmax(T &a, T b) {
  if (b > a) a = b;
}
template <class T>
inline void gmin(T &a, T b) {
  if (b < a) a = b;
}
using namespace std;
const int N = 1e5 + 10, M = 2e6 + 10, Z = 1e9 + 7, maxint = 2147483647,
          ms1 = 16843009, ms31 = 522133279, ms63 = 1061109567,
          ms127 = 2139062143;
const double PI = acos(-1.0), eps = 1e-8;
void fre() {
  freopen("/Users/luras/Desktop/in.txt", "r", stdin);
  freopen("/Users/luras/Desktop/out.txt", "w", stdout);
}
int casenum, casei;
inline int sgn(double n) { return fabs(n) < eps ? 0 : (n < 0 ? -1 : 1); }
inline double sqr(double x) { return x * x; }
inline double Sqrt(double a) { return a <= 0 ? 0 : sqrt(a); }
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 sgn(a.x - b.x) == 0 && sgn(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);
  }
  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 rotate_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));
}
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 sgn(cross(a - p.first, p.second - p.first)) <= 0;
}
inline bool satisfy2(complex<double> a,
                     pair<complex<double>, complex<double> > p) {
  return sgn(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 Halfcmp(const pair<complex<double>, complex<double> > &a,
             const pair<complex<double>, complex<double> > &b) {
  int res = sgn(arg(a.second - a.first) - arg(b.second - b.first));
  return res == 0 ? satisfy2(a.first, b) : res < 0;
}
vector<complex<double> > halfplaneIntersection(
    vector<pair<complex<double>, complex<double> > > v) {
  sort(v.begin(), v.end(), Halfcmp);
  deque<pair<complex<double>, complex<double> > > q;
  deque<complex<double> > ans;
  q.push_back(v[0]);
  for (int i = 1; i < int(v.size()); i++) {
    if (sgn(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 < int(v1.size()); i++)
    h.push_back(pair<complex<double>, complex<double> >(
        v1[i], v1[(i + 1) % v1.size()]));
  for (int i = 0; i < int(v2.size()); i++)
    h.push_back(pair<complex<double>, complex<double> >(
        v2[i], v2[(i + 1) % v2.size()]));
  return halfplaneIntersection(h);
}
double w, h, a;
point p0, p1, p2, p3, p00, p10, p20, p30;
int main() {
  while (~scanf("%lf%lf%lf", &w, &h, &a)) {
    a = a / 180 * PI;
    vector<complex<double> > v1, v2;
    p0 = point(w / 2, h / 2);
    p1 = point(-w / 2, h / 2);
    p2 = point(-w / 2, -h / 2);
    p3 = point(w / 2, -h / 2);
    v1.push_back(complex<double>(w / 2, h / 2));
    v1.push_back({-w / 2, h / 2});
    v1.push_back({-w / 2, -h / 2});
    v1.push_back({w / 2, -h / 2});
    p00 = rotate_point(p0, a);
    p10 = rotate_point(p1, a);
    p20 = rotate_point(p2, a);
    p30 = rotate_point(p3, a);
    v2.push_back({p00.x, p00.y});
    v2.push_back({p10.x, p10.y});
    v2.push_back({p20.x, p20.y});
    v2.push_back({p30.x, p30.y});
    vector<complex<double> > v0 = convexIntersection(v1, v2);
    double sum = 0;
    v0.push_back(v0[0]);
    for (int i = 0; i < v0.size() - 1; i++) {
      point t1, t2;
      t1.x = v0[i + 1].real();
      t1.y = v0[i + 1].imag();
      t2.x = v0[i].real();
      t2.y = v0[i].imag();
      sum += det(t1, t2);
    }
    printf("%.10f\n", fabs(sum / 2));
  }
  return 0;
}