P, Q, R, S, T and U live on six different floors of the same building. The lowermost floor in the building is numbered 1, the floor above it, number 2 and so on till the topmost floor is numbered 6. Q lives on an odd numbered floor but not on floor number 3. Only three people live between Q and R. S lives on an odd number floor below Q but not on the lowermost floor. R lives immediately below P. T does not live on the topmost floor. How many people live between P and U?