public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;
    }
}
*/

public class  {
    public void Mirror(TreeNode pRoot) {
        Mirror2(root);
    }
    
    public void Mirror2(TreeNode t){
        TreeNode temp = null;
        if(t != null){
            temp = t.left;
            t.left = t.right;
            t.right = temp;
            Mirror2(t.left);
            Mirror2(t.right);
        }
}