Eight people, P, Q, R, S, T, U, V and W are sitting in a straight line, facing north. Only three people sit to the left of P. Q sits third to the right of P. Only four people sit between Q and S. U sits to the immediate right of
V. R does not sit at any of the extreme ends of the line. T sits at one of the positions to the right of W. How many people sit between W and P?