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 di[] = {-1, 0, 1, 0};
const int dj[] = {0, 1, 0, -1};
const long long MOD = 1e9 + 7;
const long long INF = 1e9;
struct line {
  long double a;
  long double b;
  bool vert = false;
};
const long double PI = atan(1) * 4.0;
long double w, h, alpha;
vector<pair<long double, long double> > bf(4), af(4);
vector<line> bfl(4), afl(4), l;
pair<long double, long double> rotate(pair<long double, long double> p,
                                      double ang) {
  pair<long double, long double> ret;
  ang = ang * PI / 180.0;
  ret.second = p.second * cos(ang) - p.first * sin(ang);
  ret.first = p.second * sin(ang) + p.first * cos(ang);
  return ret;
}
inline double slope(pair<long double, long double> a,
                    pair<long double, long double> b) {
  if (a.first == b.first) return INF;
  return (a.second - b.second) / (a.first - b.first);
}
pair<long double, long double> intersect(line a, line b) {
  if (a.vert && b.vert) return make_pair(INF, INF);
  if (a.vert) return make_pair(a.a, b.a * a.a + b.b);
  if (b.vert) return make_pair(b.a, a.a * b.a + a.b);
  if (a.a == b.a) return make_pair(INF, INF);
  pair<long double, long double> ret;
  ret.first = (b.b - a.b) / (a.a - b.a);
  ret.second = a.a * ret.first + a.b;
  return ret;
}
bool cmp(pair<long double, long double> a, pair<long double, long double> b) {
  return atan2(a.second, a.first) < atan2(b.second, b.first);
}
int main() {
  ios::sync_with_stdio(false), cin.tie(0);
  cin >> w >> h >> alpha;
  if (alpha == 0 || alpha == 180 || alpha == 90 && w == h) {
    cout << fixed << setprecision(9) << w * h << endl;
    return 0;
  }
  bf[0] = make_pair(w / 2, h / 2);
  bf[1] = make_pair(w / 2, -h / 2);
  bf[2] = make_pair(-w / 2, -h / 2);
  bf[3] = make_pair(-w / 2, h / 2);
  for (int i = 0; i < 4; i++) af[i] = rotate(bf[i], 360.0 - alpha);
  for (int i = 0; i < 4; i++) {
    bfl[i].a = slope(bf[i], bf[(i + 1) % 4]);
    if (bfl[i].a == INF) {
      bfl[i].vert = true;
      bfl[i].a = bf[i].first;
    } else
      bfl[i].b = bf[i].second - bfl[i].a * bf[i].first;
    afl[i].a = slope(af[i], af[(i + 1) % 4]);
    if (afl[i].a == INF) {
      afl[i].vert = true;
      afl[i].a = af[i].first;
    } else
      afl[i].b = af[i].second - afl[i].a * af[i].first;
  }
  vector<pair<long double, long double> > pts;
  for (int i = 0; i < 4; i++)
    for (int j = 0; j < 4; j++) {
      pair<long double, long double> tmp = intersect(bfl[i], afl[j]);
      if (abs(tmp.first) <= w / 2.0 && abs(tmp.second) <= h / 2.0)
        pts.push_back(tmp);
    }
  sort(pts.begin(), pts.end(), cmp);
  long double area = 0;
  for (int i = 0; i < pts.size(); i++)
    area += pts[i].first * pts[(i + 1) % pts.size()].second -
            pts[(i + 1) % pts.size()].first * pts[i].second;
  area = abs(area) / 2.0;
  cout << fixed << setprecision(9) << area << endl;
  cin.ignore(), cin.get();
}