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 PI = acos(-1.0);
const double INF = 1e18;
struct point {
  double x, y;
  point() {}
  point(double X, double Y) {
    x = X;
    y = Y;
  }
  point rotate(double angle) {
    double tx = x * cos(angle) - y * sin(angle);
    double ty = x * sin(angle) + y * cos(angle);
    return point(tx, ty);
  }
};
struct line {
  point a, b;
  double m, c;
  line() {}
  line(point p, point q) {
    a = p;
    b = q;
    if (p.x == q.x) {
      m = INF;
      c = q.x;
    } else {
      m = (q.y - p.y) / (q.x - p.x);
      c = p.y - m * p.x;
    }
  }
  point x_at_y(double Y) {
    if (m == INF)
      return point(c, Y);
    else
      return point((Y - c) / m, Y);
  }
  point y_at_x(double X) {
    if (m == 0)
      return point(X, c);
    else
      return point(X, m * X + c);
  }
};
typedef struct point *POINT;
typedef struct line *LINE;
double distance(POINT a, POINT b) {
  return sqrt((a->x - b->x) * (a->x - b->x) + (a->y - b->y) * (a->y - b->y));
}
double area(POINT a, POINT b, POINT c) {
  double p = distance(a, b), q = distance(b, c), r = distance(a, c);
  double s = (p + q + r) / 2;
  return sqrt(s * (s - p) * (s - q) * (s - r));
}
class Task {
 public:
  void solve(istream &in, ostream &out) {
    double w, h;
    int a;
    in >> w >> h >> a;
    if (w < h) swap(w, h);
    if (a == 180 || a == 0)
      out << fixed << setprecision(12) << w * h;
    else if (a == 90)
      out << fixed << setprecision(12) << h * h;
    else {
      if (a > 90) a = 180 - a;
      double d = (double)a / 180 * PI;
      double lim = 2 * atan2(h, w);
      POINT A = new struct point(w / 2, h / 2);
      POINT B = new struct point(-w / 2, h / 2);
      POINT C = new struct point(-w / 2, -h / 2);
      POINT D = new struct point(w / 2, -h / 2);
      double ans = w * h;
      struct point RA = A->rotate(d), RB = B->rotate(d), RC = C->rotate(d),
                   RD = D->rotate(d);
      if (d < lim) {
        LINE l1 = new struct line(RA, RB);
        LINE l2 = new struct line(RA, RD);
        struct point p1 = l1->x_at_y(h / 2);
        struct point p2 = l1->y_at_x(-w / 2);
        struct point p3 = l2->x_at_y(h / 2);
        struct point p4 = l2->y_at_x(w / 2);
        double ar1 = area(B, &p1, &p2);
        double ar2 = area(A, &p3, &p4);
        ans = ans - 2 * (ar1 + ar2);
        out << fixed << setprecision(12) << ans;
      } else {
        LINE l1 = new struct line(RA, RB);
        LINE l2 = new struct line(RC, RD);
        struct point p1 = l1->x_at_y(h / 2);
        struct point p2 = l2->x_at_y(h / 2);
        double l = distance(&p1, &p2);
        out << fixed << setprecision(12) << h * l;
      }
    }
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  Task solver;
  istream &in(cin);
  ostream &out(cout);
  solver.solve(in, out);
  return 0;
}