Java Library ArrayList

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

public class ReadAndReverse {

 
  static void readAndReverse (Scanner input, PrintStream output) {
   ArrayList L = new ArrayList ();
   while (input.hasNext())
    L.add(input.next());
   for (int k = L.size() - 1; k >= 0; k -=1)
    output.printf("%s ", L.get(k));
  }
  
  public static void main (String [] args) {
   Scanner inp = new Scanner (System.in);
   readAndReverse (inp, System.out);
  }
}