Complex sentence: The Latin School of Haarlem hosts an annual Model United Nations conference: the Haarlem Model United Nations Haarlem MUN is a non-profit organization run and organized by students of the Stedelijk Gymnasium Haarlem.
Split into simpler sentences: The Latin School of Haarlem hosts an annual Model United Nations conference: the Haarlem Model United Nations (HMUN). HMUN is a non-profit organization run and organized by students of the Stedelijk Gymnasium Haarlem.