// ACM-ICPC‘“ΰ—\‘I2008 E. ‘ε‹Κ“]‚ͺ‚΅

#include <iostream>
#include <complex>
#include <stdio.h>

using namespace std;

typedef complex<double> P;
double EPS = 1e-8;

double dot(P a, P b) { return real(conj(a)*b); }
double cross(P a, P b) { return imag(conj(a)*b); }

double dist(P la, P lb, P p){
	if(dot(lb-la,p-la)<EPS) return abs(p-la);
	if(dot(la-lb,p-lb)<EPS) return abs(p-lb);
	return abs(cross(lb-la,p-la)) / abs(lb-la);
}

bool crossLine(P la, P lb, P ma, P mb){
	return cross(lb-la,ma-la)*cross(lb-la,mb-la)<0&&
		cross(mb-ma,la-ma)*cross(mb-ma,lb-ma)<0;
}

double distSquare(P la, P lb, double ma, double mb, double Ma, double Mb){
	P L[2]; L[0] = la, L[1] = lb;
	P M[4]; M[0] = P(ma,mb); M[1] = P(Ma,mb); M[2] = P(Ma,Mb); M[3] = P(ma,Mb);
	double a = dist(L[0], L[1], M[0]);
	for(int i=1;i<4;i++){
		double b = dist(L[0], L[1], M[i]);
		if(a>b) a = b;
	}
	for(int i=0;i<4;i++){
		for(int j=0;j<2;j++){
			double b = dist(M[i],M[(i+1)%4],L[j]);
			if(a>b) a = b;
		}
	}
	return a;
}

bool rightup(P a, P b){
	return real(a)<real(b)&&imag(a)<imag(b);
}

bool crossSquare(P la, P lb, double ma, double mb, double Ma, double Mb){
	if(crossLine(la,lb,P(ma,mb),P(Ma,mb))) return true;
	if(crossLine(la,lb,P(ma,mb),P(ma,Mb))) return true;
	if(crossLine(la,lb,P(Ma,mb),P(Ma,Mb))) return true;
	if(crossLine(la,lb,P(ma,Mb),P(Ma,Mb))) return true;
	if(rightup(P(ma,mb),la)&&rightup(la,P(Ma,Mb))
		&&rightup(P(ma,mb),lb)&&rightup(lb,P(Ma,Mb))) return true;
	return false;
}

int main(){
	int N;
	P a, b;
	int mx[50], my[50], Mx[50], My[50], h[50];
	while(cin >> N, N){
		int sx, sy, ex, ey; cin >> sx >> sy >> ex >> ey;
		a = P(sx,sy); b = P(ex,ey);
		for(int i=0;i<N;i++)
			cin >> mx[i] >> my[i] >> Mx[i] >> My[i] >> h[i];
		bool flag = false;
		for(int i=0;i<N;i++){
			if(crossSquare(a, b, mx[i], my[i], Mx[i], My[i])){
				flag = true;
				break;
			}
		}
		if(flag) { cout << 0 << endl; continue; }
		double r = 10000;
		for(int i=0;i<N;i++){
			double d = distSquare(a,b,mx[i],my[i],Mx[i],My[i]);
			if(d<h[i]) { if(d<r) r = d; }
			else    {
				double tmp = (d*d+h[i]*h[i])/(2*h[i]);
				if(tmp<r) r = tmp;
			}
		}
		printf("%.8lf\n", r);
	}
}