We live in flats with 3 other neighbours in our block. The occupants of one flat are young and often have friends over with the usual loud music/ slamming doors. They are always leaving cigarette ends directly outside our communal entrance. I usually pick these up as we are trying to sell our flat and it looks terrible. Am getting really sick of it now and thinking of picking them all up and stuffing them through their letterbox. Am I being unreasonable?