import javax.annotation.processing.SupportedSourceVersion;
import java.io.*;
import java.util.logging.Filter;

public class Main {

    public static void main(String[] args){
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            InputStream in = new FileInputStream("izvor.txt");
             bis = new BufferedInputStream(in);
            OutputStream out = new FileOutputStream("destinacija.txt");
             bos = new BufferedOutputStream(out);

             BufferedReader bf = new BufferedReader(new InputStreamReader(bis));

             while(bf.ready()) {
                 String s = bf.readLine();
                 if(s.charAt(0) >= '0' && s.charAt(0) <= '9') {
                     bos.write(s.getBytes());
                     bos.write(10);
                 }
             }
            bos.flush();

        }
        catch (IOException ex ){

        }
        finally {
            try {
                if(bis != null)
                  bis.close();
                if(bos != null)
                 bos.close();

            }
            catch (IOException e) {

            }
        }
    }
}