if input$1$ is None or not isinstance$($input$1,$ list$)$:

return $-1$

max$\_$version $=-1$

for file$\_$name in input$1$:

# Check if the file name follows the correct format

if isinstance$($file$\_$name, str$)$ and file$\_$name.startswith$("$File$\_")$ and file$\_$name$[5$:$].$isdigit$()$:

version $=$ int$($file$\_$name$[5$:$])$

max$\_$version $=$ max$($max$\_$version, version$)$

return max$\_$version