During physical exertion, a man with a cerebral artery aneurysm suddenly developed severe headache and vomiting and fainted. The patient is agitated and wants to run somewhere. His pulse is 62/min., rhythmic, blood pressure – 140/90 mm Hg, the body temperature is 37.5°C. He has nuchal rigidity and positive Kernig’s sign. Focal neurological signs are absent. Make the provisional diagnosis: