A 20-year-old man suffers from headache, general weakness, and face edema that appears in the morning. 18 days earlier he had a case of tonsillitis. Objectively, his skin is pale, there are edema under his eyes. Heart rate is 60/min., blood pressure is 185/100 mm Hg. The sign of costovertebral angle tenderness (punch sign in the lumbar region) is negative. Urinalysis: color of "meat slops": protein - 4.5 g/L, altered erythrocytes - 40-45 in the vision field, leukocytes - 5-6 in the vision field. 24-hour diuresis is 400 mL. What is the most likely diagnosis?