Task: Pos Tagging
Input (English): Sentence: Since September 11 , Pakistan has been repeatedly accused by Afghan and Western leaders of harbouring Taliban extremists who had pledged to disrupt the elections , {{ but }} at the highest level the US has avoided criticising President Pervaiz Musharraf on the grounds that he is helping the US catch Al Qaeda elements inside Pakistan . 
Word: but
Output (English): CCONJ