static ArrayList<Pair> surroundpr(Pair start) {
    	   // 	System.out.printf("start is (%d, %d)", start.x, start.y);
    	    	ArrayList<Pair> prlist = new ArrayList();
    	    	for (int i=0; i<4; i++) {
    	    		Pair tmp0 = new Pair(start);
    	    		//Pair tmp = new Pair();
    	    		if (i==0) {
    	    			if (start.x>0) {
    	    			Pair tmp = new Pair(start.x-1, start.y);
    	    			prlist.add(tmp);
    	    			}
    	    		}
    	    		if (i==1) {
    	    			if (start.x<size-1) {
    	    				Pair tmp = new Pair(start.x+1, start.y);
        	    			prlist.add(tmp);
    	    			}
    	    		}
    	    		if (i==2) {
    	    			if (start.y>0) {
    	    				Pair tmp = new Pair(start.x, start.y-1);
        	    			prlist.add(tmp);
    	    			}
    	    		}
    	    		if (i==3) {
    	    			if (start.y<size-1 ) {
    	    				Pair tmp = new Pair(start.x, start.y+1);
        	    			prlist.add(tmp);
    	    			}
    	    		}
    	    		
    	    	}
    	    	//for (int j=0; j<prlist.size(); j++) {
    	    		//System.out.printf("surround is (%d, %d)", prlist.get(j).x, prlist.get(j).y);
    	    	//}
    	    	return prlist;
    	    }