Study the following information carefully and answer the questions given below it.
A sales representative plans to visit each of six companies, M, N, P, Q, R and S exactly once during the course of one day. She is setting up her schedule for the day according to the following conditions.
(i) She must visit M before N and R
(ii) She must visit N before Q
(iii) The third company she visits must be P.
If the sales representative visits S first, which company must she visit second?