\documentclass{article}
\usepackage{ifthen}
\usepackage{epsfig}
\usepackage[utf8]{inputenc}
\usepackage{xcolor}
\color{white}
\pagecolor{black}
\usepackage{newunicodechar}
  \newunicodechar{⁻}{${}^{-}$}% Superscript minus
  \newunicodechar{²}{${}^{2}$}% Superscript two
  \newunicodechar{³}{${}^{3}$}% Superscript three

\pagestyle{empty}
\begin{document}
$\times$
\pagebreak

$r_0$
\pagebreak

$r_1$
\pagebreak

$\ldots$
\pagebreak

$r_{N-1}$
\pagebreak

$N$
\pagebreak

\end{document}
