public static void expand() {
		  Node root = readTrie(); // read in encoding trie
		  int N = BinaryStdIn.readInt(); // read in # of chars
		  
		  for (int i = 0; i < N; i++) {
		    Node x = root;
		    while (!x.isLeaf()) {
		      if (!BinaryStdIn.readBoolean())
		        x = x.left;  // 0
		      else
		        x = x.right; // 1
		    }
		    
		    BinaryStdOut.write(x.ch, 8); // print char
		  }
		  
		  BinaryStdOut.close();
		
	}