An elderly gentleman, with background history of dementia, previous ischaemic heart disease, hypertension, previous colorectal carcinoma (treated with right hemicolectomy), previous cholecystecytomy, was admitted from nursing home due to worsening productive cough, and increasing in shortness of breath. Patient was recently discharged from hospital around 10 days after an episode of urinary trat infection. During this latest admission, patient has no urinary symptoms, with urine dipstick and urine culture and sensitivity were normal. Patient did spike of temperature to around 38 degree celcius on admsion. His chest x ray showed left lower lobe consodilation of his lung, with elevated white cell count and CRP. What is your diagnosis ? And What will be your antibiotic of choice??