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);
int cmp(double a, double b = 0) {
  if (fabs(a - b) < 1e-8) return 0;
  if (a < b) return -1;
  return 1;
}
struct pt {
  double x, y;
  explicit pt(double x = 0, double y = 0) : x(x), y(y) {}
  pt operator+(pt q) { return pt(x + q.x, y + q.y); }
  pt operator-(pt q) { return pt(x - q.x, y - q.y); }
  pt operator*(double t) { return pt(x * t, y * t); }
  pt operator/(double t) { return pt(x / t, y / t); }
  double operator*(pt q) { return x * q.x + y * q.y; }
  double operator%(pt q) { return x * q.y - y * q.x; }
  int cmp(pt q) const {
    if (int t = ::cmp(x, q.x)) return t;
    return ::cmp(y, q.y);
  }
  bool operator==(pt q) const { return cmp(q) == 0; }
  bool operator!=(pt q) const { return cmp(q) != 0; }
  bool operator<(pt q) const { return cmp(q) < 0; }
};
struct reta {
  pt ini, fim;
  reta() {}
  reta(pt ini, pt fim) : ini(ini), fim(fim) {}
};
struct eq_reta {
  double A, B, C;
  void init(reta p) {
    pt aux = p.ini - p.fim;
    A = aux.y;
    B = -aux.x;
    C = -A * p.ini.x - B * p.ini.y;
  }
  eq_reta(reta p) { init(p); }
};
pt normal(pt v) { return pt(-v.y, v.x); }
double norma(pt v) { return hypot(v.x, v.y); }
pt versor(pt v) { return v / norma(v); }
double anglex(pt v) { return atan2(v.y, v.x); }
double angle(pt v1, pt v2) { return atan2(v1 % v2, v1 * v2); }
double triarea(pt a, pt b, pt c) { return ((b - a) % (c - a)) / 2.0; }
int ccw(pt a, pt b, pt c) { return cmp((b - a) % (c - a)); }
pt projecao(pt v, pt w) {
  double alfa = (v * w) / (w * w);
  return w * alfa;
}
double polyarea(vector<pt>& p) {
  int i, n = p.size();
  double area = 0.0;
  for (i = 0; i < n; i++) area += p[i] % p[(i + 1) % n];
  return area / 2.0;
}
int between3(pt p, pt q, pt r) {
  if (cmp((q - p) % (r - p)) == 0)
    if (cmp((q - p) * (r - p)) <= 0) return 1;
  return 0;
}
pt rotate(pt p, double ang, pt q = pt(0, 0)) {
  double s = sin(ang), c = cos(ang);
  p = p - q;
  return q + pt(p.x * c - p.y * s, p.x * s + p.y * c);
}
bool intersect_seg(pt p, pt q, pt r, pt s) {
  pt A = q - p, B = s - r, C = r - p, D = s - q;
  int a = cmp(A % C) + 2 * cmp(A % D);
  int b = cmp(B % C) + 2 * cmp(B % D);
  if (a == 3 || a == -3 || b == 3 || b == -3) return false;
  if (a || b || p == r || p == s || q == r || q == s) return true;
  int t = (p < r) + (p < s) + (q < r) + (q < s);
  return t != 0 && t != 4;
}
bool intersect_seg_2(pt p, pt q, pt r, pt s) {
  int a = ccw(p, q, r) * ccw(p, q, s);
  int b = ccw(r, s, p) * ccw(r, s, q);
  if (a < 0 && b < 0)
    return true;
  else
    return false;
  if (a > 0 || b > 0) return false;
  return (between3(p, r, s) || between3(q, r, s) || between3(r, p, q) ||
          between3(s, p, q));
}
pt acha(pt a, pt b, pt c, pt d) {
  eq_reta p(reta(a, b)), q(reta(c, d));
  pt k;
  k.x = (q.C * p.B - p.C * q.B) / (p.A * q.B - q.A * p.B);
  k.y = (q.C * p.A - p.C * q.A) / (p.B * q.A - q.B * p.A);
  return k;
}
pt pivo;
bool cmp_radial(pt a, pt b) {
  int aux = ccw(pivo, a, b);
  return ((aux < 0) || (aux == 0 && norma(a - pivo) < norma(b - pivo)));
}
bool cmp_pivo(pt p, pt q) {
  int aux = cmp(p.x, q.x);
  return ((aux < 0) || (aux == 0 && cmp(p.y, q.y) < 0));
}
vector<pt> graham(vector<pt> p) {
  int i, j, n = p.size();
  vector<pt> g;
  pivo = *min_element(p.begin(), p.end(), cmp_pivo);
  sort(p.begin(), p.end(), cmp_radial);
  for (i = j = 0; i < n; i++) {
    while (j >= 2 && ccw(g[j - 2], g[j - 1], p[i]) >= 0) {
      g.pop_back();
      j--;
    }
    g.push_back(p[i]);
    j++;
  }
  return g;
}
int main() {
  int n, m, alfa;
  scanf("%d %d %d", &n, &m, &alfa);
  if (alfa == 0 || alfa == 180) {
    printf("%.15lf\n", (double)n * (double)m);
    return 0;
  }
  vector<pt> a;
  vector<pt> b;
  a.resize(4);
  b.resize(4);
  a[0] = pt(n / 2.0, m / 2.0);
  a[1] = pt(n / 2.0, -m / 2.0);
  a[2] = pt(-n / 2.0, -m / 2.0);
  a[3] = pt(-n / 2.0, m / 2.0);
  b[0] = rotate(a[0], alfa * pi / 180.0);
  b[1] = rotate(a[1], alfa * pi / 180.0);
  b[2] = rotate(a[2], alfa * pi / 180.0);
  b[3] = rotate(a[3], alfa * pi / 180.0);
  vector<pt> p;
  for (int i = 0; i < (4); i++) {
    for (int j = 0; j < (4); j++) {
      if (intersect_seg(a[i], a[(i + 1) % 4], b[j], b[(j + 1) % 4])) {
        p.push_back(acha(a[i], a[(i + 1) % 4], b[j], b[(j + 1) % 4]));
      }
    }
  }
  p = graham(p);
  printf("%.15lf\n", fabs(polyarea(p)));
  return 0;
}