Sentence:  R. H. S. Crossman , M.P. , writing in The Manchester Guardian , states that departures from West Berlin are now running at the rate <WSD>not</WSD> of 700 , but of 1700 a week , and applications to leave have risen to 1900 a week . 
Meaning of the word marked with <WSD> tags:  negation of a word or group of words