Problem: The main land of Japan called Honshu is an island surrounded by the sea. In such an island, it is natural to ask a question: "Where is the most distant point from the sea?" The answer to this question for Honshu was found in 1996. The most distant point is located in former Usuda Town, Nagano Prefecture, whose distance from the sea is 114.86 km.

In this problem, you are asked to write a program which, given a map of an island, finds the most distant point from the sea in the island, and reports its distance from the sea. In order to simplify the problem, we only consider maps representable by convex polygons.



Input

The input consists of multiple datasets. Each dataset represents a map of an island, which is a convex polygon. The format of a dataset is as follows.


n
x1    y1
.
.
.
xn    yn


Every input item in a dataset is a non-negative integer. Two input items in a line are separated by a space.

n in the first line is the number of vertices of the polygon, satisfying 3 ≤ n ≤ 100. Subsequent n lines are the x- and y-coordinates of the n vertices. Line segments (xi, yi) - (xi+1, yi+1) (1 ≤ i ≤ n - 1) and the line segment (xn, yn) - (x1, y1) form the border of the polygon in counterclockwise order. That is, these line segments see the inside of the polygon in the left of their directions. All coordinate values are between 0 and 10000, inclusive.

You can assume that the polygon is simple, that is, its border never crosses or touches itself. As stated above, the given polygon is always a convex one.

The last dataset is followed by a line containing a single zero.

Output

For each dataset in the input, one line containing the distance of the most distant point from the sea should be output. An output line should not contain extra characters such as spaces.

The answer should not have an error greater than 0.00001 (10-5 ). You may output any number of digits after the decimal point, provided that the above accuracy condition is satisfied.

Example

Input

4
0 0
10000 0
10000 10000
0 10000
3
0 0
10000 0
7000 1000
6
0 40
100 20
250 40
250 70
100 90
0 70
3
0 0
10000 10000
5000 5001
0


Output

5000.000000
494.233641
34.542948
0.353553

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;

#define DEBUG 1

#define INF (1.0/0.0)
#define EPS 1e-8
#define PI 3.1415926535
#define EQ(x, y) (abs((x)-(y))<EPS)
#define GE(x, y) ((x)>(y)||EQ(x, y))
#define LE(x, y) ((x)<(y)||EQ(x, y))
#define X real()
#define Y imag()

typedef complex<double> Point;
typedef Point Vec;
typedef array<Point, 2> Line;
typedef vector<Point> Poly;

struct Circle {
  Point c;
  double r;
};

enum Geometry {ABC=-2, CW, ACB, CCW, CAB, ON_LINE, OUTSIDE, INSIDE, ERROR}; 

namespace std {
  bool operator<(Point a, Point b) {
    if (!EQ(a.X, b.X)) return a.X < b.X;
    if (!EQ(a.Y, b.Y)) return a.Y < b.Y;
    return false;
  }

  bool operator>(Point a, Point b) {
    return b<a;
  }

  bool operator<=(Point a, Point b) {
    return !(a>b);
  }
}

double dot(Point a, Point b) {
  return (conj(a)*b).X;
}

double cross(Point a, Point b) {
  return (conj(a)*b).Y;
}

Geometry ccw(Point a, Point b, Point c) {
  a -= b;
  c -= b;
  if (cross(a, c) > EPS) return CCW; // ccw
  if (cross(a, c) < -EPS) return CW; // cw
  if (dot(a, c) < -EPS) return ABC; // a - b - c

  double al = abs(a);
  double cl = abs(c);
  if (EQ(al, cl)) return ERROR; // a and c are duplicate
  if (EQ(min(al, cl), 0)) return ERROR;
  if (al < cl) return CAB; // c - a - b
  else return ACB; // a - c - b
}

Point proj(Line l, Point p) {
  Point v = l[1]-l[0];
  double ratio = dot(v, p-l[0]) / norm(v);
  return l[0] + ratio*v;
}

Point refl(Line l, Point p) {
  return p + (proj(l, p) - p) * 2.0;
}

Vec rotate(Vec v, double r) {
  return v*Vec(cos(r), sin(r));
}

bool IsOrthogonal(Line l, Line m) {
  Vec v1 = l[1]-l[0];
  Vec v2 = m[1]-m[0];
  return EQ(dot(v1, v2), 0.0);
}

bool IsParallel(Line l, Line m) {
  Vec v1 = l[1]-l[0];
  Vec v2 = m[1]-m[0];
  return EQ(cross(v1, v2), 0.0);
}

bool IntersectLL(Line l, Line m) {
  if (!EQ(cross(l[1]-l[0], m[1]-m[0]), 0.0)) return true;
  if (EQ(cross(l[1]-l[0], m[0]-l[0]), 0.0)) return true;
  return false;
}

bool IntersectLS(Line l, Line s) {
  Point b = l[0];
  Vec v = l[1]-l[0];
  return cross(v, s[0]-b)*cross(v, s[1]-b) < EPS;
}

bool IntersectSS(Line s, Line t) {
  // hard coding: CW := -1, CCW := 1 -> only CW*CW and CCW*CCW are equal to 1
  if (ccw(s[0], s[1], t[0])*ccw(s[0], s[1], t[1]) == 1) return false;
  swap(s, t);
  if (ccw(s[0], s[1], t[0])*ccw(s[0], s[1], t[1]) == 1) return false;
  if (!IsParallel(s, t)) return true;
  if (max(s[0], s[1]) < min(t[0], t[1])) return false;
  swap(s, t);
  if (max(s[0], s[1]) < min(t[0], t[1])) return false;
  return true;
}

bool IntersectLP(Line l, Point p) {
  return EQ(cross(l[1]-p, l[0]-p), 0.0);
}

bool IntersectSP(Line s, Point p) {
  Point a = s[0];
  Point b = s[1];
  return abs(a-p)+abs(b-p)-abs(a-b) < EPS;
}

double DistL(Line l) {
  return abs(l[0]-l[1]);
}

double DistLP(Line l, Point p) {
  return abs(p - proj(l, p));
}

double DistLL(Line l, Line m) {
  if (!IntersectLL(l, m)) return 0;
  return DistLP(l, m[0]);
}

double DistLS(Line l, Line s) {
  if (IntersectLS(l, s)) return 0;
  return min(DistLP(l, s[0]), DistLP(l, s[1]));
}

double DistSP(Line s, Point p) {
  Point r = proj(s, p);
  if (IntersectSP(s, r)) return abs(r - p);
  return min(abs(s[0]-p), abs(s[1]-p));
}

double DistSS(Line s, Line t) {
  if (IntersectSS(s, t)) return 0;

  double a = min(DistSP(s, t[0]), DistSP(s, t[1]));
  swap(s, t);
  double b = min(DistSP(s, t[0]), DistSP(s, t[1]));
  return min(a, b);
}

Line PerpendBisect(Line seg) {
  Point mid = (seg[0]+seg[1])/2.0;
  return Line{mid, mid+(seg[1]-seg[0])*Vec(0, 1)};
}

Point CrossPointLL(Line l, Line m) {
  double A = cross(l[1]-l[0], m[1]-m[0]);
  double B = cross(l[1]-l[0], l[1]-m[0]);
  if (abs(A) < EPS && abs(B) < EPS) return m[0];
  if (abs(A) < EPS) assert(0);
  return m[0] + B / A * (m[1]-m[0]);
}

vector<Point> CrossPointCL(Circle c, Line l) {
  vector<Point> ret;
  double d = DistLP(l, c.c);
  if (EQ(d, c.r)) {
    ret.emplace_back(proj(l, c.c));
  } else if (d < c.r) {
    double ratio = sqrt(c.r*c.r - d*d);
    Vec sgn = (l[0]-l[1]) / abs(l[0]-l[1]);
    ret.emplace_back(proj(l, c.c) + ratio*sgn);
    ret.emplace_back(proj(l, c.c) - ratio*sgn);
  }

  return ret;
}

vector<Point> CrossPointCS(Circle c, Line s) {
  vector<Point> ret;
  vector<Point> res = CrossPointCL(c, s);
  Point a = s[0];
  Point b = s[1];
  if (a > b) swap(a, b);
  for (Point p : res) {
    if (
      LE(a, p) 
      && 
      LE(p, b)) ret.emplace_back(p);
  }
  return ret;
}

vector<Point> CrossPointCC(Circle c1, Circle c2) {
  vector<Point> ret;
  double d = abs(c1.c - c2.c);
  double rc = (d*d + c1.r*c1.r - c2.r*c2.r) / (2*d);
  double dfr = c1.r*c1.r - rc*rc;

  if (EQ(dfr, 0.0)) dfr = 0.0;
  else if(dfr < 0.0) return ret;

  double rs = sqrt(dfr);
  Vec sgn = (c2.c - c1.c) / d;
  ret.emplace_back(c1.c + sgn*Point(rc, rs));
  if (dfr > 0.0) ret.emplace_back(c1.c + sgn*Point(rc, -rs));
  return ret;
}

// Get the intersection of a circle and a segment, which is obviously a segment
Line CapCS(Circle c, Line s) {
  Point inf(INF, INF);
  vector<Point> cros = CrossPointCS(c, s);
  if (cros.empty()) return Line{inf, inf};

  if (cros.size() == 1) {
    double ad = abs(s[0]-c.c);
    double bd = abs(s[1]-c.c);
    if (!GE(ad, min(bd, c.r))) cros.emplace_back(s[0]);
    else if (!GE(bd, min(ad, c.r))) cros.emplace_back(s[1]);
    else {
      Point p = cros[0];
      cros.emplace_back(p); // avoid an undefined behavior
    }
  }

  if (cros[1] < cros[0]) {
    swap(cros[0], cros[1]);
  }

  return Line{cros[0], cros[1]};
}

Geometry PositioningPoint(Poly poly, Point p) {
  bool in = false;
  int n = poly.size();
  for (int i=0; i<n; i++) {
    Point a = poly[i];
    Point b = poly[(i+1)%n];
    Vec u = a - p;
    Vec v = b - p;

    if (u.Y > v.Y) swap(u, v);

    double cr = cross(u, v);
    if (LE(u.Y, 0) && !GE(0, v.Y) && cr >= EPS) in ^= 1;
    if (IntersectSP({a, b}, p)) return ON_LINE;
  }

  if (in) return INSIDE;
  return OUTSIDE;
}

// Note that ccw(a, b, c) != CCW when a, b, c are colinear
Poly GrahamScan(vector<Point> ps) {
  if (ps.size() <= 2) return ps;

  int k = 0;
  int n = ps.size();
  Poly ret(n*2);

  sort(ps.begin(), ps.end());
  for (int i=0; i<n; i++) {
    while (k > 1 && ccw(ret[k-2], ret[k-1], ps[i]) != CCW) k--;
    ret[k++] = ps[i];
  }

  int k_ = k;
  for (int i=n-1; i>=0; i--) {
    while (k > k_ && ccw(ret[k-2], ret[k-1], ps[i]) != CCW) k--;
    ret[k++] = ps[i];
  }

  ret.resize(k-1);
  return ret;
}

bool IsConvex(Poly ps) {
  //return GrahamScan(ps).size() == ps.size();
  return GrahamScan(ps) == ps;
}

Poly CapConvexes(Poly pp, Poly qq) {
#if DEBUG
  assert (IsConvex(pp));
  assert (IsConvex(qq));
#endif

  Poly ret;
  int a = 0;
  int b = 0;
  int aa = 0;
  int bb = 0;
  int n = pp.size();
  int m = qq.size();
  enum {PIN, QIN, UNKNOWN} in = UNKNOWN;

  auto forward_a = [&](bool put) {
    if (put && in == PIN) ret.emplace_back(pp[a]);
    a = (a+1)%n;
    aa++;
  };

  auto forward_b = [&](bool put) {
    if (put && in == QIN) ret.emplace_back(qq[b]);
    b = (b+1)%m;
    bb++;
  };

  auto intersect_1pt = [](Point &a, Point &b, Point &c, Point &d, Point &r) {
    double D =  cross(b - a, d - c);
    if (EQ(D, 0)) return false;
    double t =  cross(c - a, d - c) / D;
    double s = -cross(a - c, b - a) / D;
    r = a + t * (b - a);
    return GE(t, 0) && LE(t, 1) && GE(s, 0) && LE(s, 1);
  };

  do {
    int apre = (a+n-1)%n;
    int bpre = (b+m-1)%m;
    double C = cross(pp[a]-pp[apre], qq[b]-qq[bpre]);
    double A = cross(pp[apre]-qq[b], pp[a]-qq[b]);
    double B = cross(qq[bpre]-pp[a], qq[b]-pp[a]);
    Point r;
    if (intersect_1pt(pp[apre], pp[a], qq[bpre], qq[b], r)) {
      if (in == UNKNOWN) aa = bb = 0;
      ret.emplace_back(r);
      if (B > 0) in = PIN;
      else if (A > 0) in = QIN;
    }

    if (EQ(A, 0) && EQ(B, 0) && EQ(C, 0)) {
      if (in == PIN) forward_b(false);
      else forward_a(false);
    } else if (C >= 0) {
      if (A > 0) forward_a(true);
      else forward_b(true);
    } else {
      if (B > 0) forward_b(true);
      else forward_a(true);
    }
  } while ((aa < n || bb < m) && aa < 2*n && bb < 2*m);

  if (in == UNKNOWN) {
    if (PositioningPoint(qq, pp[0]) != OUTSIDE) return pp;
    if (PositioningPoint(pp, qq[0]) != OUTSIDE) return qq;
  }
  return ret;
}

double CalcArea(Poly ps) {
  double ret = 0.0;
  for (int i=0; i<ps.size(); i++) {
    ret += cross(ps[i], ps[(i+1)%ps.size()]);
  }
  return ret/2.0;
}

// Convex* requires the elements of ps to be arranged counter clockwise.
pair<int, int> ConvexDiameterApexes(Poly ps) {
#if DEBUG
  assert (IsConvex(ps));
#endif

  int n = ps.size();
  int is = 0;
  int js = 0;
  for (int i=1; i<n; i++) {
    if (ps[i].Y > ps[is].Y) is = i;
    if (ps[i].Y < ps[js].Y) js = i;
  }

  int maxi, maxj;
  double maxd = norm(ps[is]-ps[js]);
  int i = is;
  int j = js;
  do {
    Vec a = ps[i+1] - ps[i];
    Vec b = ps[j+1] - ps[j];
    if (cross(a, b) > -EPS) j = (j+1)%n;
    else i = (i+1)%n;

    double d = norm(ps[i]-ps[j]);
    if (d > maxd) {
      maxd = d;
      maxi = i;
      maxj = j;
    }
  } while (i != is || j != js);

  return make_pair(maxi, maxj);
}

Line ClosestPair(vector<Point> ps) {
  auto CompareY = [](const Point &a, const Point &b) {
    if (a.Y != b.Y) return a.Y < b.Y;
    return a.X < b.X;
  };

  function<Line(Point*,int)> Rec = [&Rec, &CompareY](Point *ps, int n) {
    if (n <= 1) return Line{Point(0, 0), Point(INF, INF)};
    
    int m = n/2;
    double x = ps[m].X;
    Line a = Rec(ps, m);
    Line b = Rec(ps+m, n-m);
    double mind = DistL(a);
    Line ret = a;
    if (DistL(b) < mind) {
      mind = DistL(b);
      ret = b;
    }

    sort(ps, ps+n, CompareY);
    vector<Point> qs;
    qs.reserve(n);
    for (int i=0; i<n; i++) {
      if (abs(ps[i].X - x) >= mind) continue;

      for (int j=0; j<qs.size(); j++) {
        Point p1 = ps[i];
        Point p2 = qs[qs.size()-1-j];
        if (p1.Y - p2.Y >= mind) break;

        double d = abs(p1-p2);
        if (mind > d) {
          mind = d;
          ret = Line{p1, p2};
        }
      }

      qs.emplace_back(ps[i]);
    }

    return ret;
  };

  int n = ps.size();
  assert (n >= 2);
  sort(ps.begin(), ps.end());
  return Rec(&ps[0], n);
}

// Convex* requires the elements of ps to be arranged counter clockwise.
// <left, right> or <upper, lower>
pair<Poly, Poly> CutConvex(Poly ps, Line l) {
#if DEBUG
  assert (IsConvex(ps));
#endif

  //if (l[0].Y > l[1].Y) swap(l[0], l[1]);
  //else if (EQ(l[0].Y, l[1].Y) && l[0].X > l[1].X) swap(l[0], l[1]);

  Poly left;
  Poly right;
  for (int i=0; i<ps.size(); i++) {
    Point a = ps[i];
    Point b = ps[(i+1)%ps.size()];

    if (ccw(l[0], l[1], a) != CW) left.emplace_back(a);
    else right.emplace_back(a);

    Line m{a, b};
    if (IntersectLS(l, m)) {
      Point p = CrossPointLL(l, m);
      left.emplace_back(p);
      right.emplace_back(p);
    }
  }

  return make_pair(left, right);
}

Circle Circum(Point a, Point b, Point c) {
  Circle ret{{INF, INF}, 0.0};
  Line l{a, b};
  Line m{b, c};
  Line lp = PerpendBisect(l);
  Line mp = PerpendBisect(m);
  if (IsParallel(lp, mp)) return ret;

  ret.c = CrossPointLL(lp, mp);
  ret.r = abs(a-ret.c);
  return ret;
}

vector<Point> TangentPoints(Circle c, Point p) {
  vector<Point> ret;
  double d = abs(c.c-p);
  if (EQ(d, c.r)) {
    ret.emplace_back(p);
    return ret;
  }

  if (d < c.r) return ret;

  Vec v = (p-c.c)/d*c.r;
  double t = acos(c.r/d);
  ret.emplace_back(c.c + rotate(v, t));
  ret.emplace_back(c.c + rotate(v, -t));
  return ret;
}

vector<Line> CommonTangents(Circle p, Circle q) {
#if DEBUG
  assert(!EQ(p.c, q.c) || !EQ(p.r, q.r));
#endif

  double pr = p.r;
  double qr = q.r;
  Point pc = p.c;
  Point qc = q.c;
  double d = abs(pc - qc);
  double dr = abs(pr - qr);
  double sr = abs(pr + qr);

  vector<Line> ret;
  if (EQ(d, sr)) {
    Point cp = (pc * qr + qc * pr) / sr;
    Vec v = cp - pc;
    ret.emplace_back(Line{cp, cp + v*Vec(0, 1)});
  } else if (d > sr) {
    Point cp = (pc * qr + qc * pr) / sr;
    vector<Point> pts = TangentPoints(p, cp);
    vector<Point> qts = TangentPoints(q, cp);
    for (int i=0; i<2; i++) {
      Line l{pts[0], qts[i]};
      if (IntersectLP(l, cp)) {
        ret.emplace_back(l);
        ret.emplace_back(Line{pts[1], qts[i^1]});
      }
    }
  } 

  if (EQ(d, dr)) {
    Point cp = pc + (pc-qc) / (qr-pr) * pr;
    Vec v = cp - pc;
    ret.emplace_back(Line{cp, cp + v*Vec(0, 1)});
  } else if (d > dr) {
    if (EQ(pr, qr)) {
      Point v = (qc - pc) / d * pr;
      v *= Point(0, 1);
      ret.emplace_back(Line{pc+v, qc+v});
      ret.emplace_back(Line{pc-v, qc-v});
    } else {
      Point cp = pc + (qc-pc) * pr / (pr-qr);
      vector<Point> pts = TangentPoints(p, cp);
      vector<Point> qts = TangentPoints(q, cp);
      for (int i=0; i<2; i++) {
        Line l{pts[0], qts[i]};
        if (IntersectLP(l, cp)) {
          ret.emplace_back(l);
          ret.emplace_back(Line{pts[1], qts[i^1]});
          break;
        }
      }
    }
  } 

  return ret;
}

int N;
vector<Point> ps;

bool check(double x) {
  vector<Line> ls;
  for (int j=0; j<N; j++) {
    Line s{ps[j], ps[(j+1)%N]};
      
    Vec u = (s[1]-s[0]);
    u = (u/abs(u))*x;
    s[0] += rotate(u, PI/2);
    s[1] += rotate(u, PI/2);
    ls.emplace_back(s);
  }

  for (Line &l : ls) {
    for (Line &m : ls) {
      if (IsParallel(l, m)) continue;
      if (!IntersectSS(l, m)) continue;
      Point p = CrossPointLL(l, m);
      double d = INF;
      for (int i=0; i<N; i++) {
        Line s{ps[i], ps[(i+1)%N]};
        d = min(d, DistSP(s, p));
      }
      if (GE(d, x)) return true;
    }
  }
  return false;
}

int main() {
  while (1) {
    scanf("%d", &N);
    if (N == 0) return 0;
    ps.clear();
    for (int i=0; i<N; i++) {
      int x, y;
      scanf("%d%d", &x, &y);
      ps.emplace_back(Point(x, y));
    }
  
    double low = 0;
    double high = 100000;
    for (int i=0; i<50; i++) {
      double mid = (low+high)/2;
      if (check(mid)) low = mid;
      else high = mid;
    }
    printf("%.20f\n", low);
  }
}