#include <iostream>
#include <memory>
#include <memory.h>
#include <cmath>
#include <fstream>
#include <cmath>
#include <numeric>
#include <vector>
#include <stack>
#include <string>
#include <queue>
#include <sstream>
#include <cstdlib>
#include <cassert>
#include <cstdio>
#include <map>
#include <iomanip>
#include <list>
#include <cctype>
#include <algorithm>
#include <complex>
#define USE_MATH_DEFINES
using namespace std;

typedef complex<double> xy_t;
typedef pair<xy_t, xy_t> line;
typedef long long ll;
typedef pair<int, int> P;
typedef pair<int, P> PP;
typedef pair<int, PP> PPP;
const int INF = 1 << 29;
const double EPS = 1E-10;

namespace std{
	bool operator < (const xy_t &a, const xy_t &b){
		return real(a) != real(b) ? real(a) < real(b) : imag(a) < imag(b);
	}
}

double cross(const xy_t &a, const xy_t &b){
	return imag(conj(a) * b);
}

double dot(const xy_t &a, const xy_t &b){
	return real(conj(a)*b);
}

xy_t projection(const line &l, const xy_t &p){
	double t = dot(l.second - l.first, p - l.first) / norm(l.second - l.first);
	return l.first + t * (l.second - l.first);
}

int ccw(xy_t a, xy_t b, xy_t c){
	b -= a; c -= a;
	if(cross(b, c) > 0) return 1;
	if(cross(b, c) < 0) return -1;
	if(dot(b, c) < 0) return +2;
	if(norm(b) < norm(c) ) return -2;
	return 0;
}

bool intersectSP(const line &s, const xy_t &p){
	return abs(s.first - p) + abs(s.second - p) - abs(s.second - s.first) < EPS;
}

bool intersectSS(const line &s, const line &t){
	return ccw(s.first, s.second, t.first) * ccw(s.first, s.second, t.second) <= 0 &&
		ccw(t.first, t.second, s.first) * ccw(t.first, t.second, s.second) <= 0;
}


double distanceSP(const line &s, const xy_t p){
	xy_t r = projection(s, p);
	if(intersectSP(s, r)) return abs(r - p);
	return min(abs(s.first - p), abs(s.second - p));
}

double distanceSS(const line &s, const line &t){
	if(intersectSS(s, t)) return 0.0;
	return min(min(distanceSP(s, t.first), distanceSP(s, t.second)),
		min(distanceSP(t, s.first), distanceSP(t, s.second)));
}

xy_t crosspoint(const line &l, const line &m){
	double a = cross(l.second - l.first, m.second - m.first);
	double b = cross(l.second - l.first, l.second - m.first);
	if(abs(a) < EPS && abs(b) < EPS) return m.first;
	if(abs(a) < EPS) assert(false);
	return m.first + b / a * (m.second - m.first);
}

int n;
line ls[300];
double height[300];
line l;

bool C(double r){
	for(int i = 0; i < n * 4; i++){
		double d = distanceSS(ls[i], l);
		double dis = (height[i] < r) ? sqrt(r * r - (r - height[i]) * (r - height[i])) : r;
		if(dis > d) return false;
	}
	return true;
}

int main(){
	while(cin >> n && n){
		double sx, sy, ex, ey;
		double minx, miny, maxx, maxy, h;
		bool ok = true;
		cin >>sx >> sy >> ex >> ey;
		l = line(xy_t(sx, sy), xy_t(ex, ey));
		for(int i = 0; i < n; i++){
			cin >> minx >> miny >> maxx >> maxy >> h;
			if(minx < min(sx, ex) && max(sx, ex) < maxx && miny < min(sy, ey) && max(sy, ey) < maxy) ok = false;
			ls[i*4] = line(xy_t(minx, miny), xy_t(minx, maxy));
			ls[i*4+1] = line(xy_t(minx, maxy), xy_t(maxx, maxy));
			ls[i*4+2] = line(xy_t(maxx, maxy), xy_t(maxx, miny));
			ls[i*4+3] = line(xy_t(maxx, miny), xy_t(minx, miny));
			for(int j = 0; j < 4; j++) height[i*4+j] = h;
		}
		double ub = 1000;
		double lb = 0;

		for(int i = 0; i < 100; i++){
			double mb = (ub + lb) / 2;
			if(C(mb)) lb = mb;
			else ub = mb;
		}
		if(ok) cout << fixed << setprecision(9) << lb << endl;
		else cout << 0.0 << endl;
	}
	return 0;
}

Measured memory_bytes: 1040