import javax.swing.*;
import java.io.*;

class DueColonneDouble {
  public static void main(String[] args) throws IOException {
    String stringaInput;
    double[] numeri = new double[10];

    int i=0;
    while(i<numeri.length) {
      stringaInput = JOptionPane.showInputDialog(
        "Inserisci l'elemento in posizione " + i);
      try {
        numeri[i] = Double.parseDouble(stringaInput);
        i++;
      }
      catch(java.lang.NumberFormatException e) {
      }
      catch(java.lang.NullPointerException e) {
        JOptionPane.showMessageDialog(null, "Arrivederci!");
        System.exit(0);
      }
    }

    File fileOutput = new File("miatabella.txt");
    PrintWriter streamOutput = new PrintWriter(new FileWriter(fileOutput));

    for(i=0; i<numeri.length/2; i++)
      streamOutput.println(numeri[2*i]+"\t"+numeri[2*i+1]);

    streamOutput.close();
    System.exit(0);
  }
}