How can I determine the first page of paginated posts?

support
4 
{{- with .Paginator -}}
  {{- if and .HasNext (not .HasPrev) -}}
    I am the first page.
  {{- end -}}
  {{- if and .HasPrev (not .HasNext) -}}
    I am the last page.
  {{- end -}}
  {{- if and .HasNext .HasPrev -}}
    I am neither the first nor the last page.
  {{- end -}}
{{- end -}}