We are going to be nice to Gregory Russ on his first day as chairman of the New York City Housing Authority. Welcome, sir. From here on out, you’ll have to answer not just to the men who appointed you, Mayor de Blasio and HUD Secretary Ben Carson, but NYCHA’s 400,000 residents. Russ previously worked for public housing agencies in Minneapolis, Cambridge, Philadelphia and Chicago. NYCHA has more buildings, apartments and residents than all of those combined.