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>
#pragma comment(linker, "/STACK:64000000")
using namespace std;
const int INF = (int)1E9;
const long long INF64 = (long long)1E18;
const long double EPS = 1E-9;
const long double PI = 3.1415926535897932384626433832795;
const int MAXN = 100100;
struct point {
  long double x, y;
  explicit point(long double x = 0, long double y = 0) : x(x), y(y) {}
  void rotate(long double a) {
    long double xx = x * cos(a) - y * sin(a);
    long double yy = x * sin(a) + y * cos(a);
    x = xx, y = yy;
  }
};
struct line {
  long double A, B, C;
  line() {}
  line(const point &a, const point &b) {
    A = a.y - b.y;
    B = b.x - a.x;
    C = -(A * a.x + B * a.y);
    norm();
  }
  void norm() {
    long double z = sqrt(A * A + B * B);
    A /= z;
    B /= z;
    C /= z;
  }
  int sign(const point &p) const {
    long double d = A * p.x + B * p.y + C;
    if (abs(d) < EPS) return 0;
    return (d > 0) ? +1 : -1;
  }
};
long double dist(const point &a, const point &b) {
  return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
}
long double det(long double a, long double b, long double c, long double d) {
  return a * d - b * c;
}
point intersect(const line &l1, const line &l2) {
  long double z = det(l1.A, l1.B, l2.A, l2.B);
  return point(-det(l1.C, l1.B, l2.C, l2.B) / z,
               -det(l1.A, l1.C, l2.A, l2.C) / z);
}
int n, x[MAXN], y[MAXN];
vector<point> a;
vector<point> cut(const vector<point> &a, const line &l, int sign) {
  vector<point> ans;
  for (int i = 0; i < (int)(a.size()); i++) {
    int cur = l.sign(a[i]), j = (i + 1) % (int)a.size();
    if (cur == sign || cur == 0) ans.push_back(a[i]);
    if (cur * l.sign(a[j]) == -1) ans.push_back(intersect(l, line(a[i], a[j])));
  }
  return ans;
}
long double square(vector<point> &a) {
  long double ans = 0;
  for (int i = 0; i < (int)(a.size()); i++) {
    int j = (i + 1) % (int)a.size();
    ans += (a[i].x + a[j].x) * (a[i].y - a[j].y);
  }
  return ans;
}
int main() {
  long double w, h, al;
  cin >> w >> h >> al;
  al = al * PI / 180;
  vector<point> a;
  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 = a;
  for (int i = 0; i < (int)(b.size()); i++) b[i].rotate(al);
  for (int i = 0; i < (int)(a.size()); i++) {
    int j = (i + 1) % 4, k = (i + 2) % 4;
    line l(a[i], a[j]);
    b = cut(b, l, l.sign(a[k]));
  }
  cout.precision(15);
  cout << fixed << abs(square(b)) / 8 << endl;
  return 0;
}