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;
template <class T>
bool inside(T a, T b, T c) {
  return a <= b && b <= c;
}
int mini(int a, int b) {
  if (a < b) return a;
  return b;
}
int maxi(int a, int b) {
  if (a > b) return a;
  return b;
}
struct point {
  double x, y;
  point() {}
  point(double xx, double yy) { x = xx, y = yy; }
  bool operator<(point b) const {
    if (!(fabs(x - b.x) < 1e-9)) return x < b.x;
    return y < b.y;
  }
  bool operator==(point b) const {
    if ((fabs(x - b.x) < 1e-9) && (fabs(y - b.y) < 1e-9)) return true;
    return false;
  }
};
struct point3D {
  double x, y, z;
};
struct line {
  double a, b, c;
  line() {}
  line(point p1, point p2) {
    a = p1.y - p2.y;
    b = p2.x - p1.x;
    c = p1.x * p2.y - p2.x * p1.y;
  }
};
struct circle {
  point center;
  double r;
  circle() {}
  circle(point P, double rr) {
    center = P;
    r = rr;
  }
};
struct segment {
  point A, B;
  segment() {}
  segment(point P1, point P2) { A = P1, B = P2; }
  bool operator<(const segment &a) const { return A < a.A; }
};
struct quad {
  point p[5];
  quad() {}
  quad(point a, point b, point c, point d) {
    p[0] = a;
    p[1] = b;
    p[2] = c;
    p[3] = d;
  }
};
inline double distancepp(point a, point b) {
  return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
}
inline double sq_distance(point a, point b) {
  return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y);
}
inline double distancepl(point P, line L) {
  return fabs(L.a * P.x + L.b * P.y + L.c) / sqrt(L.a * L.a + L.b * L.b);
}
inline double cross(point p0, point p1, point p2) {
  return ((p1.x - p0.x) * (p2.y - p0.y) - (p2.x - p0.x) * (p1.y - p0.y));
}
inline bool intersection(line L1, line L2, point &p) {
  double det = L1.a * L2.b - L1.b * L2.a;
  if ((fabs(det - 0) < 1e-9)) return false;
  p.x = (L1.b * L2.c - L2.b * L1.c) / det;
  p.y = (L1.c * L2.a - L2.c * L1.a) / det;
  return true;
}
inline bool intersection(segment L1, segment L2, point &p) {
  if (!intersection(line(L1.A, L1.B), line(L2.A, L2.B), p)) {
    return false;
  }
  return ((fabs(distancepp(L1.A, p) + distancepp(L1.B, p) -
                distancepp(L1.A, L1.B)) < 1e-9) &&
          (fabs(distancepp(L2.A, p) + distancepp(L2.B, p) -
                distancepp(L2.A, L2.B)) < 1e-9));
}
inline line findPerpendicularLine(line L, point P) {
  line res;
  res.a = L.b, res.b = -L.a;
  res.c = -res.a * P.x - res.b * P.y;
  return res;
}
inline double distanceps(point P, segment S) {
  line L1 = line(S.A, S.B), L2;
  point P1;
  L2 = findPerpendicularLine(L1, P);
  if (intersection(L1, L2, P1))
    if ((fabs(distancepp(S.A, P1) + distancepp(S.B, P1) -
              distancepp(S.A, S.B)) < 1e-9))
      return distancepl(P, L1);
  return mini(distancepp(S.A, P), distancepp(S.B, P));
}
double areaPoly(point P[], int n) {
  double area = 0;
  for (int i = 0, j = n - 1; i < n; j = i++)
    area += P[j].x * P[i].y - P[j].y * P[i].x;
  return fabs(area) * .5;
}
inline bool intersectioncl(circle C, line L, point &p1, point &p2) {
  if (distancepl(C.center, L) > C.r + 1e-9) return false;
  double a, b, c, d, x = C.center.x, y = C.center.y;
  d = C.r * C.r - x * x - y * y;
  if ((fabs(L.a - 0) < 1e-9)) {
    p1.y = p2.y = -L.c / L.b;
    a = 1;
    b = 2 * x;
    c = p1.y * p1.y - 2 * p1.y * y - d;
    d = b * b - 4 * a * c;
    d = sqrt(fabs(d));
    p1.x = (b + d) / (2 * a);
    p2.x = (b - d) / (2 * a);
  } else {
    a = L.a * L.a + L.b * L.b;
    b = 2 * (L.a * L.a * y - L.b * L.c - L.a * L.b * x);
    c = L.c * L.c + 2 * L.a * L.c * x - L.a * L.a * d;
    d = b * b - 4 * a * c;
    d = sqrt(fabs(d));
    p1.y = (b + d) / (2 * a);
    p2.y = (b - d) / (2 * a);
    p1.x = (-L.b * p1.y - L.c) / L.a;
    p2.x = (-L.b * p2.y - L.c) / L.a;
  }
  return true;
}
inline bool findpointAr1Br2(point A, double r1, point B, double r2, point &p1,
                            point &p2) {
  line L;
  circle C;
  L.a = 2 * (B.x - A.x);
  L.b = 2 * (B.y - A.y);
  L.c = A.x * A.x + A.y * A.y - B.x * B.x - B.y * B.y + r2 * r2 - r1 * r1;
  C.center = A;
  C.r = r1;
  return intersectioncl(C, L, p1, p2);
}
inline double intersectionArea2C(circle C1, circle C2) {
  C2.center.x = distancepp(C1.center, C2.center);
  C1.center.x = C1.center.y = C2.center.y = 0;
  if (C1.r < C2.center.x - C2.r + 1e-9) return 0;
  if (-C1.r + 1e-9 > C2.center.x - C2.r) return acos(-1.0) * C1.r * C1.r;
  if (C1.r + 1e-9 > C2.center.x + C2.r) return acos(-1.0) * C2.r * C2.r;
  double c, CAD, CBD, res;
  c = C2.center.x;
  CAD = 2 * acos((C1.r * C1.r + c * c - C2.r * C2.r) / (2 * C1.r * c));
  CBD = 2 * acos((C2.r * C2.r + c * c - C1.r * C1.r) / (2 * C2.r * c));
  res = C1.r * C1.r * (CAD - sin(CAD)) + C2.r * C2.r * (CBD - sin(CBD));
  return .5 * res;
}
circle CircleThrough3points(point A, point B, point C) {
  double den;
  circle c;
  den = 2.0 * ((B.x - A.x) * (C.y - A.y) - (B.y - A.y) * (C.x - A.x));
  c.center.x = ((C.y - A.y) * (B.x * B.x + B.y * B.y - A.x * A.x - A.y * A.y) -
                (B.y - A.y) * (C.x * C.x + C.y * C.y - A.x * A.x - A.y * A.y));
  c.center.x /= den;
  c.center.y = ((B.x - A.x) * (C.x * C.x + C.y * C.y - A.x * A.x - A.y * A.y) -
                (C.x - A.x) * (B.x * B.x + B.y * B.y - A.x * A.x - A.y * A.y));
  c.center.y /= den;
  c.r = distancepp(c.center, A);
  return c;
}
inline point rotate2D(point P, double theta) {
  point Q;
  Q.x = P.x * cos(theta) - P.y * sin(theta);
  Q.y = P.x * sin(theta) + P.y * cos(theta);
  return Q;
}
double ang(point a, point b, point c) {
  double absq = sq_distance(a, b);
  double bcsq = sq_distance(c, b), acsq = sq_distance(a, c);
  double cosp = (absq + acsq - bcsq) / (2.0 * sqrt(absq * acsq));
  return acos(cosp);
}
double convrd(double theta) {
  double ret = 180;
  ret /= acos(-1.0);
  return ret * theta;
}
double convdr(double theta) {
  double ret = acos(-1.0);
  ret /= (double)180.0;
  return ret * theta;
}
bool inside_quad(quad q, point p) {
  double val = cross(q.p[0], q.p[1], p) * cross(q.p[3], q.p[2], p);
  if (val > 0) return 0;
  val = cross(q.p[0], q.p[3], p) * cross(q.p[1], q.p[2], p);
  if (val > 0) return 0;
  return 1;
}
bool sort_x(point a, point b) {
  if ((fabs(a.x - b.x) < 1e-9)) return a.y < b.y;
  return a.x < b.x;
}
bool sort_y(point a, point b) {
  if ((fabs(a.y - b.y) < 1e-9)) return a.x < b.x;
  return a.y < b.y;
}
point p[100100];
bool normal(const point &a, const point &b) {
  return ((fabs(a.x - b.x) < 1e-9) ? a.y < b.y : a.x < b.x);
}
bool issame(const point &a, const point &b) {
  return ((fabs(a.x - b.x) < 1e-9) && (fabs(a.y - b.y) < 1e-9));
}
void makeUnique(int &np) {
  sort(&p[0], &p[np], normal);
  np = unique(&p[0], &p[np], issame) - p;
}
bool comp(point a, point b) {
  double d = cross(p[0], a, b);
  if (d < 0) return false;
  if ((fabs(d - 0) < 1e-9) &&
      (((p[0].x - b.x) * (p[0].x - b.x)) + ((p[0].y - b.y) * (p[0].y - b.y))) <
          (((p[0].x - a.x) * (p[0].x - a.x)) +
           ((p[0].y - a.y) * (p[0].y - a.y))))
    return false;
  return true;
}
void convex_hull(point ans[], int &n, int &nc) {
  makeUnique(n);
  int i, pos = 0;
  for (i = 1; i < n; i++)
    if (p[i].y < p[pos].y || (p[i].y == p[pos].y && p[i].x < p[pos].x)) pos = i;
  swap(p[0], p[pos]);
  sort(p + 1, p + n, comp);
  ans[0] = p[0];
  if (n >= 2) ans[1] = p[1];
  for (i = nc = 2; i < n; i++) {
    while (nc >= 2 && cross(ans[nc - 2], ans[nc - 1], p[i]) < 0 ||
           (fabs(cross(ans[nc - 2], ans[nc - 1], p[i]) - 0) < 1e-9))
      nc--;
    ans[nc++] = p[i];
  }
  if (n == 1)
    nc = 1;
  else if (nc == 2) {
    if (p[0].x == p[1].x && p[0].y == p[1].y) nc = 1;
  }
}
double alpha;
double w, h;
point ps[10], psr[10];
int main() {
  int i, j, k, l, test, t = 1;
  scanf("%lf %lf %lf", &w, &h, &alpha);
  w /= 2.0;
  h /= 2.0;
  alpha = convdr(alpha);
  quad prev, now;
  ps[0] = point(-w, -h);
  ps[1] = point(w, -h);
  ps[2] = point(w, h);
  ps[3] = point(-w, h);
  prev = quad(ps[0], ps[1], ps[2], ps[3]);
  psr[0] = rotate2D(ps[0], alpha);
  psr[1] = rotate2D(ps[1], alpha);
  psr[2] = rotate2D(ps[2], alpha);
  psr[3] = rotate2D(ps[3], alpha);
  int count1 = 0;
  for (i = 0; i < 4; i++) {
    if (inside_quad(prev, psr[i])) {
      p[count1++] = psr[i];
    }
  }
  segment lines[5], linesr[5];
  lines[0] = segment(ps[0], ps[1]);
  lines[1] = segment(ps[1], ps[2]);
  lines[2] = segment(ps[2], ps[3]);
  lines[3] = segment(ps[3], ps[0]);
  linesr[0] = segment(psr[0], psr[1]);
  linesr[1] = segment(psr[1], psr[2]);
  linesr[2] = segment(psr[2], psr[3]);
  linesr[3] = segment(psr[3], psr[0]);
  for (i = 0; i < 4; i++) {
    for (j = 0; j < 4; j++) {
      point p1;
      if (intersection(lines[i], linesr[j], p1)) {
        p[count1++] = p1;
      }
    }
  }
  point c[200];
  int no;
  convex_hull(c, count1, no);
  double ans = areaPoly(c, no);
  printf("%.8lf\n", ans);
  return 0;
}