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;
double PI = acos(-1);
struct point {
  double x, y;
  int cs;
  point(double x = 0, double y = 0) {
    this->x = x;
    this->y = y;
  }
  bool operator==(point& p) { return p.x == x && p.y == y; }
  bool operator<(const point& p) const {
    if (y == p.y) return x < p.x;
    return y < p.y;
  }
  point rotate(double alpha) {
    return point(x * cos(alpha) - y * sin(alpha),
                 x * sin(alpha) + y * cos(alpha));
  }
};
struct vecto {
  double x, y;
  vecto(double x = 0, double y = 0) {
    this->x = x;
    this->y = y;
  }
  bool operator==(vecto& v) { return v.x == x && v.y == y; }
  bool operator<(const vecto& v) const {
    if (v.x == x) return y < v.y;
    return x < v.x;
  }
};
vecto toVec(point a, point b) { return vecto(b.x - a.x, b.y - a.y); }
double crossProduct(vecto a, vecto b) { return a.x * b.y - a.y * b.x; }
long long dotProduct(vecto a, vecto b) { return a.x * b.x + a.y * b.y; }
long long dist(point a, point b) {
  return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y);
}
double DEG_to_RAD(double d) { return d * PI / 180.0; }
double RAD_to_DEG(double r) { return r * 180.0 / PI; }
struct line {
  double a, b, c;
  point A, B;
  line(double a, double b, double c) : a(a), b(b), c(c) {}
  line(point A, point B) : A(A), B(B) {
    a = B.y - A.y;
    b = A.x - B.x;
    c = -(a * A.x + b * A.y);
  }
  line(point P, double m) {
    a = -m;
    b = 1;
    c = -((a * P.x) + (b * P.y));
  }
  double f(point A) { return a * A.x + b * A.y + c; }
};
double getArea(vector<point> p) {
  double area = 0;
  for (int i = (0); i <= (int((p).size()) - 1); i++) {
    int j = (i + 1) % p.size();
    area += p[i].x * p[j].y - p[j].x * p[i].y;
  }
  return fabs(area / 2.0);
}
inline int cmp(double a, double b) {
  return (a < b - 1e-6) ? -1 : ((a > b + 1e-6) ? 1 : 0);
}
bool areParallel(line l1, line l2) {
  return cmp(l1.a * l2.b, l1.b * l2.a) == 0;
}
bool areIntersect(line l1, line l2, point& p) {
  if (areParallel(l1, l2)) return false;
  double dx = l1.b * l2.c - l2.b * l1.c;
  double dy = l1.c * l2.a - l2.c * l1.a;
  double d = l1.a * l2.b - l2.a * l1.b;
  p = point(dx / d, dy / d);
  return true;
}
vector<point> polygon_cut(vector<point> P, line l) {
  vector<point> Q;
  for (int i = (0); i <= (int((P).size()) - 1); i++) {
    point A = P[i], B = P[(i + 1) % int((P).size())];
    if (crossProduct(toVec(l.A, l.B), toVec(l.A, A)) >= 0) Q.push_back(A);
    if (crossProduct(toVec(l.A, l.B), toVec(l.A, A)) *
            crossProduct(toVec(l.A, l.B), toVec(l.A, B)) <
        0) {
      point p;
      areIntersect(line(A, B), l, p);
      Q.push_back(p);
    }
  }
  return Q;
}
vector<point> cut(vector<point> P, point A, point B) {
  line l(A, B);
  P = polygon_cut(P, l);
  return P;
}
int main() {
  ios::sync_with_stdio(0);
  int n, m, alp;
  cin >> n >> m >> alp;
  if (alp == 0 || alp == 180) {
    cout << fixed << setprecision(9) << (double)n * m;
    return 0;
  }
  if (alp == 90) {
    cout << fixed << setprecision(9) << (double)min(n, m) * min(n, m);
    return 0;
  }
  double alpha = DEG_to_RAD(alp);
  point A(n / 2.0, m / 2.0);
  point B(-n / 2.0, m / 2.0);
  point C(-n / 2.0, -m / 2.0);
  point D(n / 2.0, -m / 2.0);
  point first = A.rotate(alpha);
  point second = B.rotate(alpha);
  point Z = C.rotate(alpha);
  point T = D.rotate(alpha);
  vector<point> P;
  P.push_back(A);
  P.push_back(B);
  P.push_back(C);
  P.push_back(D);
  P = cut(P, first, second);
  P = cut(P, second, Z);
  P = cut(P, Z, T);
  P = cut(P, T, first);
  cout << fixed << setprecision(9) << getArea(P);
  return 0;
}