Frozen Citadel

{t}: Add {s} or {u} to your mana pool.
{t}: Add {s}{u} to you mana pool. Only activate
this ability if you control Fallen Citadel or
Swamp Citadel.
{t} Add {s}{s}{u}{u} to your mana pool. Only
activate this ability if you control Fallen Citadel
and Swamp Citadel.