static void output(btree.node current)
 {
     if (current == null)
     {
         Console.WriteLine("Дерево пустое");
     }
     outint(current.keys[0]);
     for (int i = 1; i < current.keys.Count; i++)
     {
         Console.Write(",");
         outint(current.keys[i]);
     }
     Console.WriteLine("");
     foreach (btree.node val in current.childs)
     {
         outint(val.keys[0]);
         Console.Write(" ");
     }
     Console.WriteLine("");
     if (current.isleaf)
     {
         Console.WriteLine("----------");
     }
     foreach (btree.node val in current.childs)
     {
         output(val);
     }
 }
 static void recursion(btree treebase, btree.node treedel)
 {
     foreach (int i in treedel.keys)
     {
         treebase.Delete(i);
     }
     foreach (btree.node i in treedel.childs)
     {
         recursion(treebase, i);
     }
 }