In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.

Question: Which is the oldest country that O'Donnell served as the Resident Coordinator of the United Nations system for? Passage:Francis Martin O'Donnell, GCMM, GCEG, KC*SG, KM, KCHS, KCMCO, (born in 1954), an Irish citizen, has served abroad as an international diplomat in senior representative positions with the United Nations until retirement, and later with the Sovereign Military Order of Malta. He is a life member of the Institute of International and European Affairs (under the patronage of the President of Ireland). He currently continues to serve pro bono as an advisor to the Global Partnerships Forum  founded by Amir Dossal, and is a listed endorser of the NGO consortium known as Nonviolent Peaceforce . He served as Ambassador Extraordinary and Plenipotentiary of the Sovereign Military Order of Malta to the Slovak Republic from December 2009 to March 2013. 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. In early 2012, he was appointed to the Council of the Order of Clans of Ireland (under the patronage of the President of Ireland), and was elected its Chancellor in May 2014 . He also served on the Board of Directors, and completed both terms of office in April 2015. Since then, he has participated in Globsec, the InterAction Council, and is a regular participant, panelist or moderator in the annual Global Baku Forum. He is also a speaker and panelist on global policy issues to seminars and forums of the Association of Schools of Political Studies of the Council of Europe, and occasional guest speaker on Irish history and genealogy in Dublin, Madrid, Vienna, and at the Sorbonne in Paris.

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