private void convertCSV() throws IOException {
		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) {
				
				// we split the line according to spaces
				String[] split = thisLine.split(",");
				// for each value
				for (String value : split) {
					// we convert to integer and write the item
					Integer item = Integer.parseInt(value);
					writer.write(item + " -1 ");   // write an itemset separator
				}
				writer.write("-2");    // write end of line
				
				count++; // increase the number of sequences
				// if we have read enough sequences, we stop.
				if(count == lineCount){
					break;
				}
				writer.newLine(); // create new line
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (myInput != null) {
				myInput.close();
			}
		}
	}