15.
Seven people, L, M, N, O, W, X and Y, are sitting in a row, facing north (but not necessarily in the same order). Only two people sit to the left of Y. Only three people sit between Y and W. X sits second to the right of Y. Only two people sit between X and M. L sits at some place to the right of O but at some place to the left of N. How many people sit to the right of L?