(S (S (ADVP (BASENP (NN Three) (NNS years)) (RB ago)) (COMMA ,) (S (BASENP (NNP Thessaloniki)) (VP (VBD was) (NP (BASENP (DT the) (NN host) (NN city)) (PP (IN of) (BASENP (DT the) (NN 2003) (NNP European) (NNP Union) (NNP Summit))))))) (PERIOD .))