General Studies · Puzzle / Box Arrangement

Seven boxes P, Q, R, S, T, U and V are kept one over the other but not necessarily in the same order. No box is kept above U. Only three boxes are kept between U and P. Only one box is kept between R and T. T is kept immediately above P. Only four boxes are kept between R and V. Q is kept at some place above S. How many boxes are kept between S and U?