A 20-year-old homeless and unemployed patient complains about body temperature rise up to 39°C, pain during eating and deglutition, nasal hemorrhages. He has been suffering from this for 10 days. Objectively: herpetic rash on the lips, irregular-shaped erosions covered with fibrinous deposit on the mucous membrane of oral cavity; filmy deposits on the tonsils. Liver is enlarged and sclerotic. Blood count: erythrocytes - 4,5 × 1012/l; hemoglobin - 120 g/l; ESR - 25 mm/h; leukocytes - 10 × 109/l; eosinophils - 0; rod nuclear cells - 2; segmentonuclear leukocytes - 31, lymphocytes - 41; monocytes - 10; atypical mononuclears - 14%, plasmatic cells - 2. What is the most probable diagnosis?