// Jim
import java.io.File;
public class stuff
{
  public static boolean isPower2(int n)
  {
    return n >= 1 && (n == 2 || isPower2(n / 2));
  }
  public ListNode reverse(ListNode head)
  {
    if(head == null)
      return null;
    return new ListNode(head.getValue(), reverse(head.getNext()));
  }
  private boolean isWord(String s)
  {
    return s.length() > 0 & Character.isLetter(s.charAt(0)) && 
           (s.length() == 1 || isWord(s.substring(0)));
  }
  public boolean isPhrase(String s)
  {
    String[] words = s.split(" ");
    return isWord(words[0]) && 
           (words[0].length() == s.length() || 
           isPhrase(s.substring(words[0].length()+1)));
  }
  public long getTotalSize(File x)
  {
    if(!x.isDirectory())
      return x.length();
    else
    {
      long size = 0;
      File[] files = x.listFiles();
      for(File thisfile:files)
      {
        size += getTotalSize(thisfile);
      }
      return size;
    }
  }
  public int getSum(int[][] grid, int r, int c)
  {
    int sum = 0;
    if(r >= 0 && c >= 0 && r < grid.length && 
       c < grid[0].length && grid[r][c] > 0)
    {
      grid[r][c] = 0;
      sum += getSum(grid, r-1, c);
      sum += getSum(grid, r+1, c);
      sum += getSum(grid, r, c-1);
      sum += getSum(grid, r, c+1);
    }
    return sum;
  }
}