import java.util.Scanner;

public class E {

	static final double EPS = 1.0e-5;

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		while (true) {
			int n = in.nextInt();
			if (n == 0)
				break;
			double ans = Double.MAX_VALUE;
			V s1 = new V();
			s1.x = in.nextDouble();
			s1.y = in.nextDouble();
			V s2 = new V();
			s2.x = in.nextDouble();
			s2.y = in.nextDouble();
			for (int i = 0; i < n; i++) {
				double x1 = in.nextDouble();
				double y1 = in.nextDouble();
				double x2 = in.nextDouble();
				double y2 = in.nextDouble();
				double h = in.nextDouble();
				if (isCollSegs(s1, s2, new V(x1, y1), new V(x2, y2))) {
					ans = 0;
				} else if (isCollSegs(s1, s2, new V(x1, y2), new V(x2, y1))) {
					ans = 0;
				}
				double d = segPoint(s1, s2, new V(x1, y1));
				double r = Math.min(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(s1, s2, new V(x1, y2));
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(s1, s2, new V(x2, y1));
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(s1, s2, new V(x2, y2));
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);

				d = segPoint(new V(x1, y1), new V(x2, y1), s1);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(new V(x1, y1), new V(x2, y1), s2);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);

				d = segPoint(new V(x1, y1), new V(x1, y2), s1);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(new V(x1, y1), new V(x1, y2), s2);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);

				d = segPoint(new V(x2, y1), new V(x2, y2), s1);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(new V(x2, y1), new V(x2, y2), s2);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);

				d = segPoint(new V(x1, y2), new V(x2, y2), s1);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);
				d = segPoint(new V(x1, y2), new V(x2, y2), s2);
				r = Math.max(d, (d * d + h * h) / (2 * h));
				ans = Math.min(r, ans);

			}
			System.out.printf("%.5f%n", ans);
		}
	}

	static double segPoint(V a, V b, V p) {
		V t1 = b.sub(a);
		V t2 = p.sub(a);
		if (t1.dot(t2) < EPS)
			return t2.length();
		t1 = a.sub(b);
		t2 = p.sub(b);
		if (t1.dot(t2) < EPS)
			return t2.length();
		return Math.abs(t1.cross(t2) / t1.length());
	}

	static boolean isCollSegs(V a1, V a2, V b1, V b2) {
		V t1 = a2.sub(a1);
		V t2 = b1.sub(a1);
		V t3 = b2.sub(a1);
		double m1 = t1.cross(t2) * t1.cross(t3);
		t1 = b2.sub(b1);
		t2 = a1.sub(b1);
		t3 = a2.sub(b1);
		double m2 = t1.cross(t2) * t1.cross(t3);
		return m1 < EPS && m2 < EPS;
	}

}

class V {
	double x, y;

	public V() {
	}

	public V(double x, double y) {
		this.x = x;
		this.y = y;
	}

	V sub(V v) {
		return new V(x - v.x, y - v.y);
	}

	double length() {
		return Math.sqrt(x * x + y * y);
	}

	double dot(V v) {
		return x * v.x + y * v.y;
	}

	double cross(V v) {
		return x * v.y - y * v.x;
	}
}