Go Golang - variadic function, find greatest number in list

Go Golang - variadic function, find greatest number in list

package main
 
import "fmt"
 
func greatestNumber(args ... int) int {
	max := int(0)
	for _, arg := range args {
		if arg > max {
			max = arg
		}
	}
	return max
}
func main() {
    fmt.Println(greatestNumber(12,3,84,32,52,97,6))
}

fails when called with only negative numbers; also when passed no args.
can address both issues by changing line 6 to be:

max := args[0]