private void convertSnake() {
		String thisLine; // variable to read a line
		BufferedReader myInput = null;  
		try {
			// Objects to read the file
			FileInputStream fin = new FileInputStream(new File(input));
			myInput = new BufferedReader(new InputStreamReader(fin));
			
			int count =0;  // to count the number of line
			
			// we read the file line by line until the end of the file
			while ((thisLine = myInput.readLine()) != null) {
				// if the line contains more than 11 elements
				// (we use this to filter smaller lines)
				if(thisLine.length() >= 11){   
					// for each integer on this line, we consider that it is an item
					for(int i=0; i< thisLine.length(); i++){
						// we subtract 65 to get the item number and
						// write the item to the file
						int character = thisLine.toCharArray()[i] - 65;
						// we write an itemset separator
						writer.write(character + " -1 ");   
					}
					// we write the end of the line
					writer.write("-2");
				}
				count++; // we increase the number of line that was read until now
				
				// if we have read enough lines, we stop.
				if(count == lineCount){
					break;
				}
				// start a new line
				writer.newLine();
			}
			myInput.close();
		} catch (Exception e) {
			e.printStackTrace();
		} 
	}