Definition: In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Input: Context: He previously served as a United Nations official for 32 years, most recently as the Resident Coordinator of the United Nations system in Ukraine, from 30 September 2004 until 31 March 2009, and previously in the same capacity in Serbia-Montenegro Link Information: According to the Peace of Riga, western Ukraine was incorporated into Poland, which in turn recognised the Ukrainian Soviet Socialist Republic in March 1919 Question: Which is the oldest country that O'Donnell served as the Resident Coordinator of the United Nations system for?
Output:
Answer: Serbia