private static void obhod(Uzel u)
{
if (u.left != null)
obhod(u.left);
Console.WriteLine(u.value);
if (u.right != null)
obhod(u.right);
}
static void Main(string[] args)
{
Uzel root = new Uzel();
root.value = Console.ReadLine()[0];
while (true)
{
string s =Console.ReadLine();
if (s.Equals("quit"))
break;
AddUzel(root,s.ToCharArray()[0]);
}
obhod(root);
Console.ReadLine();
}
private static void AddUzel(Uzel u, char v)
{
if (u.value < v && u.right == null)
{
Uzel subu = new Uzel();
subu.value = v;
u.right = subu;
}
else if (u.value >= v && u.left == null)
{
Uzel subu = new Uzel();
subu.value = v;
u.left = subu;
}
else if (u.value < v && u.right != null)
{
AddUzel(u.right,v);
}
else if (u.value >= v && u.left != null)
{
AddUzel(u.left, v);
}
return;
}