#include <iostream>
#include <fstream>

using namespace std;

int w, h, n;

bool rt[101][101];
bool up[101][101];

int sx, sy, sd;

void input(istream &cin , bool b)
{
	int x, y, xx, yy;
	cin >> x >> y >> xx >> yy;
	if(x==xx)
	{
		int my = y<?yy;
		int mm = y>?yy;
		if(b==0)
		{
			sx=x, sy=my, (sd=(x?2:0));
			if(x==0)
				;
			else
				sx--;
		}

		for(int j=my; j<mm; j++) up[x][j] = b;
	}
	if(y==yy)
	{
		int mx = x<?xx;
		int mm = x>?xx;
		if(b==0) sx=mx, sy=y, (sd=(y?3:1));
		if(b==0)
		{
			if(y)
				sy--;
		}
		for(int j=mx; j<mm; j++) rt[j][y] = b;
	}
	//cerr<<"sx="<<sx<<" sy="<<sy<<endl;
}

int dx[] = {1,0,-1,0};
int dy[] = {0,1,0,-1};

bool func(int x, int y, int d)
{
	d &= 3;
	switch(d)
	{
		case 0: return up[x+1][y  ]==0;
		case 1: return rt[x  ][y+1]==0;
		case 2: return up[x  ][y  ]==0;
		case 3: return rt[x  ][y  ]==0;
	}
}

main()
{
	fstream cin("B.txt");
	while(cin>>w>>h>>n && w+h+n)
	{
		//cerr<<__LINE__<<endl;
		memset(rt, 0, sizeof(rt));
		memset(up, 0, sizeof(up));
		//cerr<<__LINE__<<endl;
		for(int i=0; i<n; i++)
		{
			input(cin, 1);
		}
		for(int y=0; y<h; y++) up[0][y]=1;
		for(int y=0; y<h; y++) up[w][y]=1;
		for(int x=0; x<w; x++) rt[x][0]=1;
		for(int x=0; x<w; x++) rt[x][h]=1;
		input(cin, 0);

		int gx, gy;
		cin >> gx >> gy;

		int x=sx, y=sy;
		int d=sd;

		x -= dx[d]; y -= dy[d]; /* sagaru */
		int ssx = x , ssy = y;
		int cnt=0;
		//cerr<<"sx="<<sx<<" sy="<<sy<<endl;
		while(!(x==gx && y==gy))
		{
			//cerr<<"x="<<x<<" y="<<y<<" d="<<d<<endl;
			if(cnt>0 && x==ssx && y==ssy)
			{
				cnt=-1;
				break;
			}
			cnt++;
			if(func(x,y,d))
			{
				x+=dx[d];
				y+=dy[d];
				d++; d%=4;
			}
			else if(func(x,y,d=(d+3)%4))
			{
				x+=dx[d];
				y+=dy[d];
				d++; d%=4;
			}
			else if(func(x,y,d=(d+3)%4))
			{
				x+=dx[d];
				y+=dy[d];
				d++; d%=4;
			}
			else if(func(x,y,d=(d+3)%4))
			{
				x+=dx[d];
				y+=dy[d];
				d++; d%=4;
			}
			else
			{
				//cerr<<"error: "<<__LINE__<<endl;
			}
		}
		if(cnt<0)
			cout << "Impossible"<<endl;
		else
			cout << cnt << endl;
	}
	return 0;
}