public void parseInputFile() throws IOException{
		BufferedReader reader = new BufferedReader( new FileReader(inputFileName));
		String line = null;
		
		int y = 0;
		while( (line = reader.readLine()) != null) {
			
			if(xmax == -1) {
				xmax = line.length();
			}
			HashMap<Integer,Position> ythRow = new HashMap<Integer,Position>();
			for(int x = 0; x<line.length(); x++) {
				
				Position n = new Position();
				n.x = x;
				n.y = y;
				n.data = line.charAt(x);
				ythRow.put(x,n);
				if(n.data != ' ' && n.data != '*') {
					nodes.put(n.data, n);
				}
			}
			maze.put(y,ythRow);
			y++;
		}
		ymax = y;
		reader.close();
		calculateNeighbours();
	}