P, Q, R, S, T and U are six brothers. Q is younger than P, but elder than S. T is elder than P. R and U are twins. P is elder than R and Q is younger than U. Who is the eldest?

P, Q, R, S, T and U are six brothers. Q is younger than P, but elder than S. T is elder than P. R and U are twins. P is elder than R and Q is younger than U. Who is the eldest?