Aseer plays a simple game with DFS. In each turn, everyone tosses a coin. If the two coins are both face up or back up, no one will win the game. Otherwise, the one whose coin is face up get one score, and the other lose one score.

Aseer wants to know the expectation of the absolute value of his final score after t turns. But he is a little bit stupid, so he asks you to help him calculate the answer.