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(-1.0);
const double eps = 1e-10, big = 10000.0;
const int maxn = 20010;
struct point {
  double x, y;
};
struct polygon {
  int n;
  point p[maxn];
};
struct line {
  point a, b;
};
double at2[maxn];
int ord[maxn], dq[maxn + 1], lnum, n;
polygon pg;
line ls[maxn];
int N = 0;
double t;
struct Edge {
  point a, b;
  Edge() {}
  Edge(double x, double y, double xx, double yy) {
    a.x = x, a.y = y, b.x = xx, b.y = yy;
  }
  Edge(point aa, point bb) { a = aa, b = bb; }
};
inline int sig(double k) { return (k < -eps) ? -1 : k > eps; }
inline double multi(point o, point s, point e) {
  return (s.x - o.x) * (e.y - o.y) - (e.x - o.x) * (s.y - o.y);
}
point isIntersected(point s1, point e1, point s2, point e2) {
  double dot1, dot2;
  point pp;
  dot1 = multi(s2, e1, s1);
  dot2 = multi(e1, e2, s1);
  pp.x = (s2.x * dot2 + e2.x * dot1) / (dot2 + dot1);
  pp.y = (s2.y * dot2 + e2.y * dot1) / (dot2 + dot1);
  return pp;
}
inline bool cmp(int u, int v) {
  if (sig(at2[u] - at2[v]) == 0)
    return sig(multi(ls[v].a, ls[v].b, ls[u].b)) >= 0;
  return at2[u] < at2[v];
}
bool judgein(int x, int y, int z) {
  point pnt = isIntersected(ls[x].a, ls[x].b, ls[y].a, ls[y].b);
  return sig(multi(ls[z].a, ls[z].b, pnt)) < 0;
}
void HalfPlaneIntersection() {
  int n = lnum, tmpn, i;
  for (i = 0; i < n; i++) {
    at2[i] = atan2(ls[i].b.y - ls[i].a.y, ls[i].b.x - ls[i].a.x);
    ord[i] = i;
  }
  sort(ord, ord + n, cmp);
  for (i = 1, tmpn = 1; i < n; i++)
    if (sig(at2[ord[i - 1]] - at2[ord[i]]) != 0) ord[tmpn++] = ord[i];
  n = tmpn;
  int bot = 1, top = bot + 1;
  dq[bot] = ord[0];
  dq[top] = ord[1];
  for (i = 2; i < n; i++) {
    while (bot < top && judgein(dq[top - 1], dq[top], ord[i])) top--;
    while (bot < top && judgein(dq[bot + 1], dq[bot], ord[i])) bot++;
    dq[++top] = ord[i];
  }
  while (bot < top && judgein(dq[top - 1], dq[top], dq[bot])) top--;
  while (bot < top && judgein(dq[bot + 1], dq[bot], dq[top])) bot++;
  dq[--bot] = dq[top];
  pg.n = 0;
  for (i = bot + 1; i <= top; i++)
    pg.p[pg.n++] = isIntersected(ls[dq[i - 1]].a, ls[dq[i - 1]].b, ls[dq[i]].a,
                                 ls[dq[i]].b);
}
inline void add(double a, double b, double c, double d) {
  ls[lnum].a.x = a;
  ls[lnum].a.y = b;
  ls[lnum].b.x = c;
  ls[lnum].b.y = d;
  lnum++;
}
point rotate(double x, double y) {
  point ret;
  ret.x = x * cos(t) + y * sin(t);
  ret.y = y * cos(t) - x * sin(t);
  return ret;
}
int main() {
  double w, h;
  cin >> w >> h >> t;
  w /= 2.0;
  h /= 2.0;
  t = t * pi / 180.0;
  add(-w, -h, w, -h);
  add(w, -h, w, h);
  add(w, h, -w, h);
  add(-w, h, -w, -h);
  Edge E;
  E = Edge(rotate(-w, -h), rotate(w, -h));
  add(E.a.x, E.a.y, E.b.x, E.b.y);
  E = Edge(rotate(w, -h), rotate(w, h));
  add(E.a.x, E.a.y, E.b.x, E.b.y);
  E = Edge(rotate(w, h), rotate(-w, h));
  add(E.a.x, E.a.y, E.b.x, E.b.y);
  E = Edge(rotate(-w, h), rotate(-w, -h));
  add(E.a.x, E.a.y, E.b.x, E.b.y);
  int n = 8, i;
  HalfPlaneIntersection();
  double area = 0;
  n = pg.n;
  for (i = 0; i < n; i++)
    area += pg.p[i].x * pg.p[(i + 1) % n].y - pg.p[(i + 1) % n].x * pg.p[i].y;
  area = fabs(area) / 2.0;
  printf("%.10f\n", area);
  return 0;
}