This Tuesday, February 24 marks four years since Russia launched its full-scale invasion of Ukraine, forcing millions to flee their homes. Today there are an estimated four million Internally Displaced Persons (IDPs) in Ukraine. As the front line moves, endangering areas that were previously considered relatively safe, the shortage of suitable long-term accommodation options for these IDPs remains chronic. FRANCE 24's Gulliver Cragg, Illia Dyadik and Catalina Gomez report.