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 INF = 1 << 29;
const double PI = acos(-1);
const double EPS = 1e-8;
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 cross(const complex<double> &a, const complex<double> &b) {
  return imag(conj(a) * b);
}
double dot(const complex<double> &a, const complex<double> &b) {
  return real(conj(a) * b);
}
struct L : public vector<complex<double> > {
  L(const complex<double> &a, const complex<double> &b) {
    push_back(a);
    push_back(b);
  }
  L() {}
};
struct C {
  complex<double> p;
  double r;
  C(const complex<double> &p, double r) : p(p), r(r) {}
};
int ccw(complex<double> a, complex<double> b, complex<double> c) {
  b -= a;
  c -= a;
  if (cross(b, c) > 0) return +1;
  if (cross(b, c) < 0) return -1;
  if (dot(b, c) < 0) return +2;
  if (norm(b) < norm(c)) return -2;
  return 0;
}
bool intersectLL(const L &l, const L &m) {
  return abs(cross(l[1] - l[0], m[1] - m[0])) > EPS ||
         abs(cross(l[1] - l[0], m[0] - l[0])) < EPS;
}
bool intersectLS(const L &l, const L &s) {
  return cross(l[1] - l[0], s[0] - l[0]) * cross(l[1] - l[0], s[1] - l[0]) <
         EPS;
}
bool intersectLP(const L &l, const complex<double> &p) {
  return abs(cross(l[1] - p, l[0] - p)) < EPS;
}
bool intersectSS(const L &s, const L &t) {
  return ccw(s[0], s[1], t[0]) * ccw(s[0], s[1], t[1]) <= 0 &&
         ccw(t[0], t[1], s[0]) * ccw(t[0], t[1], s[1]) <= 0;
}
bool intersectSS2(const L &s, const L &t) {
  for (int i = 0; i < (int)2; ++i) {
    if (ccw(s[0], s[1], t[i]) == 0) {
      int c = ccw(s[0], s[1], t[!i]);
      if (s[0] == t[i]) {
        if (c != -2 && c) return 0;
      } else if (s[1] == t[i]) {
        if (c != 2 && c) return 0;
      } else if (abs(c) == 1)
        return 0;
    }
  }
  return ccw(s[0], s[1], t[0]) * ccw(s[0], s[1], t[1]) <= 0 &&
         ccw(t[0], t[1], s[0]) * ccw(t[0], t[1], s[1]) <= 0;
}
bool intersectSP(const L &s, const complex<double> &p) {
  return abs(s[0] - p) + abs(s[1] - p) - abs(s[1] - s[0]) < EPS;
}
complex<double> projection(const L &l, const complex<double> &p) {
  double t = dot(p - l[0], l[0] - l[1]) / norm(l[0] - l[1]);
  return l[0] + t * (l[0] - l[1]);
}
complex<double> reflection(const L &l, const complex<double> &p) {
  return p + complex<double>(2, 0) * (projection(l, p) - p);
}
double distanceLP(const L &l, const complex<double> &p) {
  return abs(p - projection(l, p));
}
double distanceLL(const L &l, const L &m) {
  return intersectLL(l, m) ? 0 : distanceLP(l, m[0]);
}
double istanceLS(const L &l, const L &s) {
  if (intersectLS(l, s)) return 0;
  return min(distanceLP(l, s[0]), distanceLP(l, s[1]));
}
double distanceSP(const L &s, const complex<double> &p) {
  const complex<double> r = projection(s, p);
  if (intersectSP(s, r)) return abs(r - p);
  return min(abs(s[0] - p), abs(s[1] - p));
}
double distanceSS(const L &s, const L &t) {
  if (intersectSS(s, t)) return 0;
  return min(min(distanceSP(s, t[0]), distanceSP(s, t[1])),
             min(distanceSP(t, s[0]), distanceSP(t, s[1])));
}
complex<double> crosspoint(const L &l, const L &m) {
  double A = cross(l[1] - l[0], m[1] - m[0]);
  double B = cross(l[1] - l[0], l[1] - m[0]);
  if (abs(A) < EPS && abs(B) < EPS) return m[0];
  if (abs(A) < EPS) assert(false);
  return m[0] + B / A * (m[1] - m[0]);
}
double area(const vector<complex<double> > &g) {
  double A = 0;
  for (int i = 0; i < g.size(); ++i) {
    A += cross(g[i], g[(i + 1) % g.size()]);
  }
  return abs(A / 2);
}
vector<complex<double> > convex_cut(const vector<complex<double> > &g,
                                    const L &l) {
  vector<complex<double> > Q;
  for (int i = 0; i < (int)g.size(); ++i) {
    complex<double> A = g[i], B = g[(i + 1) % g.size()];
    if (ccw(l[0], l[1], A) != -1) Q.push_back(A);
    if (ccw(l[0], l[1], A) * ccw(l[0], l[1], B) < 0)
      Q.push_back(crosspoint(L(A, B), l));
  }
  return Q;
}
complex<double> centroid(const vector<complex<double> > &v) {
  double S = 0;
  complex<double> res;
  for (int i = 0; i < (int)v.size(); ++i) {
    int j = i + 1;
    if (j == v.size()) j = 0;
    double tmp = cross(v[i], v[j]);
    S += tmp;
    res += (v[i] + v[j]) * tmp;
  }
  S /= 2;
  res /= 6 * S;
  return res;
}
double manDistanceSP(const L &l, const complex<double> &p) {
  double res = INF;
  L xl = L(p, p + complex<double>(1, 0));
  if (intersectLS(xl, l)) {
    complex<double> cp = crosspoint(xl, l);
    double d = abs(p - cp);
    res = min(res, d);
  }
  L yl = L(p, p + complex<double>(0, 1));
  if (intersectLS(yl, l)) {
    complex<double> cp = crosspoint(yl, l);
    double d = abs(p - cp);
    res = min(res, d);
  }
  res = min(res, abs(l[0].real() - p.real()) + abs(l[0].imag() - p.imag()));
  res = min(res, abs(l[1].real() - p.real()) + abs(l[1].imag() - p.imag()));
  return res;
}
bool convex_contain(const vector<complex<double> > &g,
                    const complex<double> &p) {
  for (int i = 0; i < (int)g.size(); ++i)
    if (ccw(g[i], g[(i + 1) % g.size()], p) == -1) return 0;
  return 1;
}
bool intersectGG(const vector<complex<double> > &g1,
                 const vector<complex<double> > &g2) {
  if (convex_contain(g1, g2[0])) return 1;
  if (convex_contain(g2, g1[0])) return 1;
  for (int i = 0; i < (int)g1.size(); ++i)
    for (int j = 0; j < (int)g2.size(); ++j) {
      if (intersectSS(L(g1[i], g1[(i + 1) % g1.size()]),
                      L(g2[j], g2[(j + 1) % g2.size()])))
        return 1;
    }
  return 0;
}
double distanceGP(const vector<complex<double> > &g, const complex<double> &p) {
  if (convex_contain(g, p)) return 0;
  double res = INF;
  for (int i = 0; i < (int)g.size(); ++i) {
    res = min(res, distanceSP(L(g[i], g[(i + 1) % g.size()]), p));
  }
  return res;
}
L bisector(const complex<double> &a, const complex<double> &b) {
  complex<double> A = (a + b) * complex<double>(0.5, 0);
  return L(A, A + (b - a) * complex<double>(0, PI / 2));
}
vector<complex<double> > voronoi_cell(vector<complex<double> > g,
                                      const vector<complex<double> > &v,
                                      int s) {
  for (int i = 0; i < (int)v.size(); ++i)
    if (i != s) g = convex_cut(g, bisector(v[s], v[i]));
  return g;
}
double angle(const complex<double> &a, const complex<double> &b) {
  double ret = arg(b) - arg(a);
  return (ret >= 0) ? ret : ret + 2 * PI;
}
double angle2(const complex<double> &a, const complex<double> &b) {
  return min(angle(a, b), angle(b, a));
}
double rtod(double rad) { return rad * 180 / PI; }
double dtor(double deg) { return deg * PI / 180; }
complex<double> rotate(complex<double> p, double ang) {
  return p * complex<double>(cos(ang), sin(ang));
}
L rotate(L l, double ang) { return L(rotate(l[0], ang), rotate(l[1], ang)); }
int main() {
  double w, h, a;
  while (cin >> w >> h >> a) {
    w /= 2;
    h /= 2;
    a = dtor(a);
    vector<complex<double> > g;
    g.push_back(complex<double>(-w, -h));
    g.push_back(complex<double>(w, -h));
    g.push_back(complex<double>(w, h));
    g.push_back(complex<double>(-w, h));
    vector<complex<double> > g2 = g;
    for (__typeof((g2).begin()) it = (g2).begin(); it != (g2).end(); ++it) {
      *it = rotate(*it, a);
    }
    for (int i = 0; i < (int)4; ++i) {
      g = convex_cut(g, L(g2[i], g2[(i + 1) % 4]));
    }
    double ans = area(g);
    printf("%.10f\n", ans);
  }
}