Подскажите, пожалста, что не правильно?
public class Solution {
    public static void main(String[] args) {
        try (Scanner scanner = new Scanner(System.in);
             var inputStream = Files.newInputStream(Paths.get(scanner.nextLine()));
             var outputStream = Files.newOutputStream(Paths.get(scanner.nextLine()))
        ) {
            int size = 16384;
            byte[] buffer = new byte[size];
            while (inputStream.available() > 0) {
                if(inputStream.available() < 2){
                    int read = inputStream.read(buffer);
                    outputStream.write(buffer, 0, read);
                } else {
                    int read1 = inputStream.read(buffer);
                    int read2 = inputStream.read(buffer);
                    outputStream.write(buffer, 0, read2);
                    outputStream.write(buffer, 0, read1);
                }
            }
        } catch (Exception e){
            e.printStackTrace();
        }
    }
}