import java.io.*;
import java.util.*;

// reverse linked list

 class switchLinked
 {public static input in = new input();

 public static void fill(LinkedList l)
  {for (int x = 1; x <= 9; x++)
    {
		l.add(new Integer((int)(Math.random()*100+1)));
}
  }


public static void switcher(LinkedList l)  // switch every other
  {
		int spot = 0;
		int size = l.size();
		Integer i;
		while (spot < size-1)
		  {i = l.remove(spot+1);
		   l.add(spot,i);

			spot+=2;
	      }

  }

 public static void main(String[] args) throws IOException
  {LinkedList l = new LinkedList();
   fill(l);
   System.out.println(l);
   switcher(l);
   System.out.println(l);
}
}