

You are a specialist in playing 6-handed No Limit Texas Holdem. The following will be a game scenario and you need to make the optimal decision.

Here is a game summary:

The small blind is 0.5 chips and the big blind is 1 chips. Everyone started with 100 chips.
The player positions involved in this game are UTG, HJ, CO, BTN, SB, BB.
In this hand, your position is UTG, and your holding is [Six of Spade and Six of Club].
Before the flop, UTG raise 2.0 chips, and BTN call. Assume that all other players that is not mentioned folded.
The flop comes Jack Of Heart, Four Of Heart, and Five Of Spade, then UTG check, and BTN check.
The turn comes King Of Heart, then UTG check, BTN bet 6 chips, and UTG call.
The river comes Eight Of Diamond, then UTG check, and BTN bet 13 chips.


Now it is your turn to make a move.
To remind you, the current pot size is 30.0 chips, and your holding is [Six of Spade and Six of Club].

Decide on an action based on the strength of your hand on this board, your position, and actions before you. Do not explain your answer.
Your optimal action is: