A 52 y.o. male patient has become ill gradually. There is pain in the left side of the thorax during 2 weeks, elevation of temperature till 38 - 39°C. On examination: left chest side falls behind in breathing movement no voice tremor over the left lung. Dullness that is more intensive in lower parts of this lung. Right heart border is deviated outside. Sharply weakened breathing over the left lung, no rales. Heart sounds are mufflet, tachycardia. What is the most probable diagnosis?