A 52-year-old man had an acute onset of the disease after an overexposure to cold that occurred 3 weeks ago. He complains of cough, high body temperature of 30.5°C chest pain on the right, and marked dyspnea. His pulse is 120/min., blood pressure 90/60 mm Hg, respiration rate 48/min. Acrocyanosis is observed. Objectively, the right side of his chest lags behind during breathing. Percussion detects a pulmonary dullness on the right. Auscultation detects no breathing over the right lung. X-ray shows on the right a shadow with fuzzy upper margin to the level of rib II. Exudate contains 90% of neutrophils. What is the most likely. diagnosis in this case?