private static void run(String file1, String file2) throws IOException {
Tree t = buildTree(file1);
Tree s = buildTree(file2);
t.toDotFile("/home/milon/1.dot", true);
s.toDotFile("/home/milon/2.dot", true);
CostFunction w = new CostFunction() {
@Override
public double cost(NodeLabel l1, NodeLabel l2) {