Study the information carefully and answer the questions given below
P, Q, R, S, T and V are six students studying in a class. Each of them has a different height and weight. The tallest is not the heaviest. T is taller than only P but lighter than R. Q is taller than S and P and heavier than only T and V. P is lighter than only S. T is heavier than V. S is taller than V and Q is not the tallest.
How many of them are shorter than Q?