import java.io.IOException;
import java.util.StringTokenizer;
import java.util.Vector;
class Main {
static int maxLg = 200;
static int n, m, l;
static int pc;
public static void main(String args[]) throws Exception {
for (int i = 0; i != m; i++) {
walls[i] = new Reta();
tel[i] = new Point();
tel[i].tel = true;
}
String t[];
while (true) {
t = split(readLine());
n = Integer.parseInt(t[0]);
m = Integer.parseInt(t[1]);
l = Integer.parseInt(t[2]);
if (n == 0 && m == 0 && l == 0)
break;
pc = 0;
for (int i = 0; i != m; i++) {
t = split(readLine());
walls[i].clear(Integer.parseInt(t[0]), Integer.parseInt(t[1]),
Integer.parseInt(t[2]), Integer.parseInt(t[3]));
points[pc++] = walls[i].p1;
points[pc++] = walls[i].p2;
}
for (int i = 0; i != l; i++) {
t = split(readLine());
tel[i].clear(Integer.parseInt(t[0]), Integer.parseInt(t[1]));
points[pc++] = tel[i];
}
Point s = new Point();
t = split(readLine());
s.clear(Integer.parseInt(t[0]), Integer.parseInt(t[1]));
Point e = new Point();
t = split(readLine());
e.x = Integer.parseInt(t[0]);
e.y = Integer.parseInt(t[1]);
e.end = true;
points[pc++] = e;
start(s);
}
}
private static void start(Point s) {
// tento ir para cada local possivel
Vector v = new Vector();
v.addElement(s);
Reta menor = null;
Reta temp = new Reta();
Reta r;
s.dist = 0;
while (v.size() != 0) {
double minDist = 0;
menor = null;
Point p = (Point) v.elementAt(0);
v.removeElement(p);
// para todos os caminhos possiveis
for (int i = 0; i != pc; i++) {
if (points[i].p) {
temp.clear(s, points[i]);
if (!possivel(temp))
continue;
if (minDist < temp.dist
|| (minDist == temp.dist && points[i].end == true)
|| menor == null) {
if (menor == null) {
temp = new Reta();
menor = temp;
} else {
r = menor;
menor = temp;
temp = r;
}
}
}
}
if (menor == null) {
// nao achou nada!!???
while (true)
;
}
if (menor.p2.end) {
System.out.println(Math.round(p.dist + menor.dist));
return;
}
// se for um TELEPORTE???
menor.p2.dist = p.dist + menor.dist;
v.addElement(menor.p2);
}
// nao achou nada!!! impossivel!!!
while (true)
;
}
private static boolean possivel(Reta temp) {
for (int i = 0; i != m; i++) {
if (temp.cruza(walls[i]))
return false;
}
return true;
}
static String[] split(String s) {
StringTokenizer st = new StringTokenizer(s.trim(), " ");
String[] tokens = new String[st.countTokens()];
for (int i = 0; i != tokens.length; i++) {
tokens[i] = st.nextToken();
}
return tokens;
}
// le uma linha inteira
static String readLine() throws IOException {
byte lin[] = new byte[maxLg];
int lg = 0, car = -1;
while (lg < maxLg) {
car = System.in.read();
if ((car < 0) || (car == '\n')) {
break;
}
lin[lg++] += car;
}
if ((car < 0) && (lg == 0)) {
return (null); // eof
}
return (new String(lin, 0, lg));
}
static long[] splitLongLine(String s) {
String[] l = split(s);
long v[] = new long[l.length];
for (int i = 0; i != l.length; i++) {
v[i] = Long.valueOf(l[i]).longValue();
}
return v;
}
}