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;
struct Point {
  long double x, y;
  Point() {}
  Point(long double x, long double y) : x(x), y(y) {}
} O(0, 0);
Point operator*(const Point &A, const long double &K) {
  return Point(A.x * K, A.y * K);
}
Point operator+(const Point &A, const Point &B) {
  return Point(A.x + B.x, A.y + B.y);
}
Point operator-(const Point &A, const Point &B) {
  return Point(A.x - B.x, A.y - B.y);
}
bool operator<(const Point &a, const Point &b) {
  if (a.x != b.x) return a.x < b.x;
  return a.y < b.y;
}
long double cross(const Point &A, const Point &B) {
  return A.x * B.y - A.y * B.x;
}
long double area(const Point &A, const Point &B, const Point &C) {
  return cross(B - A, C - A);
}
bool between(const Point &A, const Point &B, const Point &P) {
  return P.x + (1e-8) >= min(A.x, B.x) && P.x <= min(A.x, B.x) + (1e-8) &&
         P.y + (1e-8) >= min(A.y, B.y) && P.y <= min(A.y, B.y) + (1e-8);
}
bool onSegment(const Point &A, const Point &B, const Point &P) {
  return abs(area(A, B, P)) < (1e-8) && between(A, B, P);
}
bool intersects(const Point &P1, const Point &P2, const Point &P3,
                const Point &P4) {
  long double A1 = area(P3, P4, P1);
  long double A2 = area(P3, P4, P2);
  long double A3 = area(P1, P2, P3);
  long double A4 = area(P1, P2, P4);
  if (A1 * A2 < (1e-8) && A3 * A4 < (1e-8)) return 1;
  if (onSegment(P3, P4, P1)) return 1;
  if (onSegment(P3, P4, P2)) return 1;
  if (onSegment(P1, P2, P3)) return 1;
  if (onSegment(P1, P2, P4)) return 1;
  return 0;
}
bool pointInPoly(vector<Point> &Poly, Point P) {
  int nP = Poly.size(), cnt = 0;
  for (int i = 0; i < (nP); i++) {
    if (onSegment(Poly[i], Poly[(i + 1) % nP], P)) return 0;
    cnt += intersects(Poly[i], Poly[(i + 1) % nP], P,
                      P + Point(1000000009, 1000000007));
  }
  return cnt & 1;
}
vector<Point> ConvexHull(vector<Point> Poly) {
  sort(Poly.begin(), Poly.end());
  int nP = Poly.size(), k = 0;
  Point H[2 * nP];
  for (int i = 0; i < nP; ++i) {
    while (k >= 2 && area(H[k - 2], H[k - 1], Poly[i]) <= 0) --k;
    H[k++] = Poly[i];
  }
  for (int i = nP - 2, t = k; i >= 0; --i) {
    while (k > t && area(H[k - 2], H[k - 1], Poly[i]) <= 0) --k;
    H[k++] = Poly[i];
  }
  if (k == 0) return vector<Point>();
  return vector<Point>(H, H + k - 1);
}
Point lineIntersection(const Point &A, const Point &B, const Point &C,
                       const Point &D) {
  return A + (B - A) * (cross(C - A, D - C) / cross(B - A, D - C));
}
long double area(const vector<Point> &P) {
  int nP = P.size();
  long double A = 0;
  for (int i = 1; i <= nP - 2; i++) A += area(P[0], P[i], P[i + 1]);
  return abs(A / 2);
}
Point rot(Point P, long double angle) {
  long double X = P.x * cos(angle) - P.y * sin(angle);
  long double Y = P.x * sin(angle) + P.y * cos(angle);
  return Point(X, Y);
}
int main() {
  long double W, H, a;
  while (cin >> W >> H >> a) {
    vector<Point> A;
    W /= 2, H /= 2;
    A.push_back(Point(W, H));
    A.push_back(Point(-W, H));
    A.push_back(Point(-W, -H));
    A.push_back(Point(W, -H));
    vector<Point> B(4);
    for (int i = 0; i < (4); i++) B[i] = rot(A[i], a * acos(-1.0) / 180.0);
    vector<Point> Poly;
    for (int i = 0; i < (4); i++)
      if (pointInPoly(A, B[i])) Poly.push_back(B[i]);
    for (int i = 0; i < (4); i++)
      if (pointInPoly(B, A[i])) Poly.push_back(A[i]);
    for (int i = 0; i < (4); i++)
      for (int j = 0; j < (4); j++)
        if (intersects(A[i], A[(i + 1) % 4], B[j], B[(j + 1) % 4]) &&
            abs(cross(A[i] - A[(i + 1) % 4], B[j] - B[(j + 1) % 4])) > (1e-8)) {
          Point Inter =
              lineIntersection(A[i], A[(i + 1) % 4], B[j], B[(j + 1) % 4]);
          Poly.push_back(Inter);
        }
    for (int i = 0; i < (4); i++)
      for (int j = 0; j < (4); j++)
        if (onSegment(A[i], A[(i + 1) % 4], B[j])) Poly.push_back(B[j]);
    for (int i = 0; i < (4); i++)
      for (int j = 0; j < (4); j++)
        if (onSegment(B[i], B[(i + 1) % 4], A[j])) Poly.push_back(A[j]);
    Poly = ConvexHull(Poly);
    printf("%.10f\n", double(area(Poly)));
  }
}