#include<iostream>
#include<algorithm>
#include<cmath>
#include<vector>
#include<complex>
#include<cassert>
#include<iomanip>
#define REP(i,s,n) for(int i=s;i<n;i++)
#define rep(i,n) REP(i,0,n)
#define EPS (1e-10)
#define inf (1<<29)
#define COUNTER_CLOCKWISE 1
#define CLOCKWISE -1 
#define ONLINE_BACK 2
#define ONLINE_FRONT -2
#define ON_SEGMENT 0
#define equals(a,b) (fabs((a)-(b)) < EPS)

using namespace std;

class Point
{
  public:
  double x,y;

  Point(double x = -inf,double y = -inf): x(x),y(y){}

  Point operator + (Point p ){return Point(x+p.x,y+p.y);}
  Point operator - (Point p){return Point(x-p.x,y-p.y);}
  Point operator * (double a){return Point(a*x,a*y);}
  Point operator / (double a){return Point(x/a,y/a);}//※イケメンに限る

};

struct Segment
{
  Point p1,p2;
  Segment(Point p1 = Point(),Point p2 = Point()):p1(p1),p2(p2){}
};
typedef Point Vector;
typedef Segment Line;
typedef vector<Point> Polygon;

double dot(Point a,Point b)
{
  return a.x*b.x + a.y*b.y;
}
double cross(Point a,Point b)
{
  return a.x*b.y - a.y*b.x;
}

double norm(Point a)
{
  return a.x*a.x+a.y*a.y;
}

double abs(Point a)
{
  return sqrt(norm(a));
}

int ccw(Point p0,Point p1,Point p2)
{
  Point a = p1-p0;
  Point b = p2-p0;
  if(cross(a,b) > EPS)return COUNTER_CLOCKWISE;
  if(cross(a,b) < -EPS)return CLOCKWISE;
  if(dot(a,b) < -EPS)return ONLINE_BACK;
  if(norm(a) < norm(b))return ONLINE_FRONT;
  return ON_SEGMENT;
}

double getDistanceLP(Line s,Point p)
{
  return abs(cross(s.p2-s.p1,p-s.p1))/abs(s.p2-s.p1);
}

double getDistanceSP(Segment s,Point p)
{
  if(dot(s.p2-s.p1,p-s.p1) < 0.0)return abs(p-s.p1);
  if(dot(s.p1-s.p2,p-s.p2) < 0.0)return abs(p-s.p2);
  return getDistanceLP(s,p);
}

struct Circle
{
  Point p;
  double r;
  Circle(Point p=Point(),double r=inf):p(p),r(r){}
};

bool isIntersect(Point p1,Point p2,Point p3,Point p4)
{
  return (ccw(p1,p2,p3) * ccw(p1,p2,p4) <= 0 &&
          ccw(p3,p4,p1) * ccw(p3,p4,p2) <= 0 );
}

bool isIntersect(Segment s1,Segment s2)
{
return isIntersect(s1.p1,s1.p2,s2.p1,s2.p2);
}

//cross product of pq and pr
double cross3p(Point p,Point q,Point r)
{
  return (r.x-q.x) * (p.y -q.y) - (r.y - q.y) * (p.x - q.x);
}
  
//returns true if point r is on the same line as the line pq
bool collinear(Point p,Point q,Point r)
{
  return fabs(cross3p(p,q,r)) < EPS;
}

//returns true if point t is on the left side of line pq
bool ccwtest(Point p,Point q,Point r)
{
  return cross3p(p,q,r) > 0;//can be modified to accept collinear points
}

bool onSegment(Point p,Point q,Point r)
{
  return collinear(p,q,r) && equals(sqrt(pow(p.x-r.x,2)+pow(p.y-r.y,2)) + sqrt(pow(r.x-q.x,2) + pow(r.y-q.y,2) ),sqrt(pow(p.x-q.x,2)+pow(p.y-q.y,2)) ) ;
}

bool isConvex(vector<Point> p)
{
  int sz = (int)p.size();
  
  if(sz < 3)return false;//boundary case, we treat a point or a line as not convex  
  bool isLeft = ccwtest(p[0],p[1],p[2]);
  
  for(int i=1; i<(int)p.size();i++)
    if(ccwtest(p[i],p[(i+1)%sz],p[(i+2)%sz]) != isLeft)
      return false;
  
  return true;
}


double angle(Point a,Point b,Point c)
{
  double ux = b.x - a.x, uy = b.y - a.y;
  double vx = c.x - a.x, vy = c.y - a.y;
  return acos((ux*vx + uy*vy)/sqrt((ux*ux + uy*uy) * (vx*vx + vy*vy)));
}  
  
//多角形poly内（線分上も含む）に点pが存在するかどうは判定する  
bool inPolygon(Polygon poly,Point p)
{
  if((int)poly.size() == 0)return false;

  //polyの最後の要素 = polyの最初の要素 であることが前提
  
  //そうでない場合は
    rep(i,poly.size())
      if(onSegment(poly[i],poly[(i+1)%poly.size()],p))return true;
    double sum = 0;
    for(int i=0; i < (int)poly.size() ;i++)
      {
        if(cross3p(p,poly[i],poly[(i+1)%poly.size()]) < 0)
          sum -= angle(p,poly[i],poly[(i+1)%poly.size()]);
        else
          sum += angle(p,poly[i],poly[(i+1)%poly.size()]);
      }
      return (fabs(sum - 2*M_PI) < EPS || fabs(sum + 2*M_PI) < EPS); 
}  


Point project(Segment s,Point p)
{
  Vector base = s.p2 - s.p1;
  double t = dot(p-s.p1,base)/norm(base);
  return s.p1 + base*t;
}

double getDistance(Segment s1,Segment s2)
{
  if(isIntersect(s1,s2))return 0;
  return min( min(getDistanceSP(s1,s2.p1), getDistanceSP(s1,s2.p2) ),
	      min(getDistanceSP(s2,s1.p1), getDistanceSP(s2,s1.p2) ));
}
//-------------------------------
bool intersectLL(Line l, Line m) {
  return abs(cross(l.p2-l.p1, m.p2-m.p1)) > EPS || // non-parallel
         abs(cross(l.p2-l.p1, m.p1-l.p1)) < EPS;   // same line
}
bool intersectLS(Line l, Line s) {
  return cross(l.p2-l.p1, s.p1-l.p1)*       // s[0] is left of l
         cross(l.p2-l.p1, s.p2-l.p1) < EPS; // s[1] is right of l
}
bool intersectLP(Line l,Point p) {
  return abs(cross(l.p2-p, l.p1-p)) < EPS;
}
bool intersectSS(Line s, Line t) {
  return ccw(s.p1,s.p2,t.p1)*ccw(s.p1,s.p2,t.p2) <= 0 &&
         ccw(t.p1,t.p2,s.p1)*ccw(t.p1,t.p2,s.p2) <= 0;
}
bool intersectSP(Line s, Point p) {
  return abs(s.p1-p)+abs(s.p2-p)-abs(s.p2-s.p1) < EPS; // triangle inequality
}

Point projection(Line l,Point p) {
  double t = dot(p-l.p1, l.p1-l.p2) / norm(l.p1-l.p2);
  return l.p1 + (l.p1-l.p2)*t;
}
Point reflection(Line l,Point p) {
  return p + (projection(l, p) - p) * 2;
}
double distanceLP(Line l, Point p) {
  return abs(p - projection(l, p));
}
double distanceLL(Line l, Line m) {
  return intersectLL(l, m) ? 0 : distanceLP(l, m.p1);
}

double distanceLS(Line l, Line s) {
  if (intersectLS(l, s)) return 0;
  return min(distanceLP(l, s.p1), distanceLP(l, s.p2));
}
double distanceSP(Line s, Point p) {
  Point r = projection(s, p);
  if (intersectSP(s, r)) return abs(r - p);
  return min(abs(s.p1 - p), abs(s.p2 - p));
}

double distanceSS(Line s, Line t) {
  if (intersectSS(s, t)) return 0;
  return min(min(distanceSP(s, t.p1), distanceSP(s, t.p2)),
             min(distanceSP(t, s.p1), distanceSP(t, s.p2)));
}
Point crosspoint(Line l, Line m) {
  double A = cross(l.p2 - l.p1, m.p2 - m.p1);
  double B = cross(l.p2 - l.p1, l.p2 - m.p1);
  if (abs(A) < EPS && abs(B) < EPS) return m.p1; // same line
  if (abs(A) < EPS) assert(false); // !!!PRECONDITION NOT SATISFIED!!!
  return m.p1 +   (m.p2 - m.p1) * (B / A);
}
//------------------------------------------^^^

struct Obj
{
  vector<Point> ps;
  double h;
  Obj(Point ps1=Point(),Point ps2=Point(),double h=-inf):h(h)
  {
    ps.clear();
    ps.resize(4);
    ps[0].x = ps1.x,ps[0].y = ps1.y;
    ps[1].x = ps1.x,ps[1].y = ps2.y;
    ps[2].x = ps2.x,ps[2].y = ps2.y;
    ps[3].x = ps2.x,ps[3].y = ps1.y;
  }
};
int N;
Point s,e;

int main()
{

  while(cin >> N,N)
    {
      cin >> s.x >> s.y >> e.x >> e.y;  

      Obj vec;
      Circle c(s);
      Segment seg(s,e);
      rep(i,N)
	{
	  Point a,b;
	  double h;
	  cin >> a.x >> a.y >> b.x >> b.y >> h;
	  if(c.r == 0)continue;
	  vec = Obj(a,b,h);
	  rep(j,4)
	    {
	      if(isIntersect(seg,Segment(vec.ps[j],vec.ps[(j+1)%4])) )
		{
		  c.r = 0;
		  break;
		}
	    }

	  if(inPolygon(vec.ps,s) || inPolygon(vec.ps,e))
	    {
	      c.r = 0;
	      continue;
	    }

	  rep(j,4)
	    {
	      double w = distanceSS(seg,Segment(vec.ps[j],vec.ps[(j+1)%4]));
  //double w = getDistance(seg,Segment(vec.ps[j],vec.ps[(j+1)%4]));
	      double dist = (h*h+w*w)/(2.0*h);
	      if(!equals(w,h) && w < h)dist = w;

	      c.r = min(c.r,dist);
	    }

	}
      cout << setiosflags(ios::fixed) << setprecision(10) << c.r << endl;
    }
  return 0;
}

Measured memory_bytes: 1356