You are planning a pooled (multi-session) host pool for 400 knowledge workers who run Microsoft 365 apps, Edge, and Teams. Microsoft guidance classifies these users as 'medium' workload. Your standard is to place no more than 4 users per vCPU and to use memory-optimized-balanced VMs. You select the Standard_D8s_v5 SKU (8 vCPU, 32 GB RAM). Assuming you want approximately 20% spare capacity for peaks and want to base capacity on the vCPU ratio, how many Standard_D8s_v5 session hosts should you deploy?