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 MAX_N = 101;
const double eps = 1e-9;
const double pi = acos(-1.0);
double w, h, a;
template <class T>
T Abs(T x) {
  return x < 0 ? -x : x;
}
double sgn(double x) { return fabs(x) < eps ? 0 : (x < eps ? -1 : 1); }
class node {
 public:
  double x, y;
  node(double _x = 0, double _y = 0) { x = _x, y = _y; }
  node(const node &A) {
    x = A.x;
    y = A.y;
  }
  node &operator=(const node &A) {
    x = A.x;
    y = A.y;
    return (*this);
  }
};
struct seg {
  node s, t;
  seg() {}
  seg(const node &s_, const node &t_) : s(s_), t(t_) {}
};
double Cross(node a, node b, node c) {
  return (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
}
double Area(node a, node b, node c) {
  return 0.5 * Abs((b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x));
}
double Len(node a, node b) {
  return sqrt(eps + (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
}
double Len(node a) { return sqrt(eps + a.x * a.x + a.y * a.y); }
node its(seg a, seg b) {
  double s1 = Area(b.s, b.t, a.s), s2 = Area(b.s, b.t, a.t);
  return node((a.s.x * s2 + a.t.x * s1) / (s1 + s2),
              (a.s.y * s2 + a.t.y * s1) / (s1 + s2));
}
bool sct(node a1, node a2, node b1, node b2) {
  if (sgn(Cross(a1, b1, b2)) == 0 && sgn(Cross(a2, b1, b2)) == 0) {
    if (Abs(Abs(Len(a1, b1) - Len(a2, b2)) - (Len(a1, a2) + Len(b1, b2))) < eps)
      return false;
    if (Abs(Abs(Len(a1, b2) - Len(a2, b1)) - (Len(a1, a2) + Len(b1, b2))) < eps)
      return false;
    return true;
  }
  if (sgn(Cross(a1, b1, b2) * Cross(a2, b1, b2)) > 0) return false;
  if (sgn(Cross(b1, a1, a2) * Cross(b2, a1, a2)) > 0) return false;
  return true;
}
node Rotate(node a, double angle) {
  return node(a.x * cos(angle) - a.y * sin(angle),
              a.x * sin(angle) + a.y * cos(angle));
}
node wc[MAX_N], pp[MAX_N], p[5], q[5];
int x, n, m;
bool cmp(node a, node b) { return atan2(a.y, a.x) > atan2(b.y, b.x); }
void solve() {
  if (a == 0 || a == 180) {
    printf("%.9lf\n", w * h);
    return;
  }
  w /= 2, h /= 2;
  q[0] = node(w, h);
  q[1] = node(-w, h);
  q[2] = node(-w, -h);
  q[3] = node(w, -h);
  double rad = pi * a / 180;
  for (int i = 0; i < 4; ++i) p[i] = Rotate(q[i], rad);
  int n = 0;
  for (int i = 0; i < 4; ++i) {
    int j = (i + 1) % 4;
    for (int k = 0; k < 4; ++k) {
      if (sct(p[i], p[j], q[k], q[(k + 1) % 4])) {
        seg l1(p[i], p[j]), l2(q[k], q[(k + 1) % 4]);
        wc[++n] = its(l1, l2);
      }
    }
  }
  int m = 0;
  for (int i = 1; i <= n; ++i) {
    bool update = false;
    for (int j = 1; j < i; ++j) {
      if (sgn(wc[i].x - wc[j].x) == 0 && sgn(wc[i].y - wc[j].y) == 0)
        update = true;
    }
    if (!update) pp[++m] = wc[i];
  }
  if (0 == m) {
    printf("%.9lf\n", w * h * 4);
    return;
  }
  sort(pp + 1, pp + m + 1, cmp);
  pp[0] = node(0.0, 0.0);
  double area = 0;
  for (int i = 1; i <= m; ++i) {
    int j = (i + 1) % (m + 1);
    if (0 == j) ++j;
    area += Abs(Area(pp[i], pp[j], pp[0]));
  }
  printf("%.9lf\n", area);
}
int main() {
  scanf("%lf%lf%lf", &w, &h, &a);
  solve();
  return 0;
}