A 42-year-old patient complains of a painful ulcer in the mouth that is getting bigger and does not heal over 1,5 months. Objectively: on the buccal mucosa there is a shallow soft ulcer 2 cm in diameter with irregular undermined edges. The ulcer floor is uneven and covered with yellow-gray coating. The ulcer is surrounded by many small yellowish tubercles. Regional lymph nodes are elastic, painful, matted together. Which disease is characterized by such symptoms?