What is the highest fixed acidity among the top 5 highest quality wines (quality=8)?

What is the highest fixed acidity among the top 5 highest quality wines (quality=8)?: a task in SmolDataEnvs-harbor-train-sandbox: 📊 SmolDataEnvs: Harbor (train) (Harbor dataset). Files (in /home/user/input, no subfolders): - winequality-red.csv