General Studies · Seating Arrangement

Seven persons M, N, O, P, Q, R, and S are sitting in a row facing south (not necessarily in the same order). R is not at either extreme end of the row. P sits 5th to the right of M. Two persons sit between M and R. P and R are not immediate neighbors of each other. S sits second to the left of R. N sits 4th to the right of O. Who is at the 3rd position from the left end and the right end respectively?