#include <iostream.h>
#include <fstream.h>

ifstream from("video.in");

int main(void)
{
  int xstart, ystart, x,y,x0init,y0init,x1init,y1init,xalt,yalt;
  int x0,y0,x1,y1;
  int k=0;
  while(1)
    {
     k++;
      int n;
      from >> n;
      if(n==0) exit(0);
      from>>xstart;x=xstart;
      from>>ystart;y=ystart;
     x0init=0;x1init=0;
     y0init=0;y1init=0;
      for(int i=0;i<n;i++)
	  {
	    xalt=x;
	    yalt=y;
	  
	    if(i==n-1)
	      {
		x=xstart;
		y=ystart;
	      }
	    else
	      {
		from>>x;
		from >>y;
	      }
	    if(x<xalt)
	      if(y0init==0 || y>=y0)
		{
		  y0=y;
		  y0init=1;
		}
	    if(x>xalt)
	      if(y1init==0 || y<=y1)
		{
		  y1init=1;
		  y1=y;
		}
	    if(y>yalt)
	      if(x0init==0 || x>=x0)
		{
		  x0init=1;
		  x0=x;
		}
	    if(y<yalt)
	      if(x1init==0 || x<=x1)
		{
		  x1init=1;
		  x1=x;
		}
	    
	  }
      cout <<"Floor #" << k<<endl;
     if(x0<=x1 && y0<=y1)
       {
	 cout << "Surveillance is possible."<<endl;
       }
     else
       {
	 cout <<"Surveillance is impossible."<<endl;
       }
     cout << endl;
    }
      return 0;
}