If S is absent from the office for a day, which of the following employee CANNOT receive any memoranda from any other employee on the that day ? 

In an office there are exactly seven employees - N, P, Q, R, S, T and U. An employee can pass along any memoranda written by that employee as well as any memoranda received from others, but only according to specific rule "Mumoranda can be passed in either dircetion between P and Q, is either direction between R and U, and is either direction between S and T. "Momoranda can be paused from N to S, from Q to R, from S to P, form U to N and from U to Q."