documentclass{standalone}
usepackage{tikz}
usetikzlibrary{calc, positioning}
defd{0.7cm}
tikzset{
  >=latex,
  font=sffamily,
  mybox/.style={rectangle, fill=white, thin, draw, outer sep=0, minimum width = d, minimum height = d, inner sep=0},
}
begin{document}
begin{tikzpicture}
foreachk/s in {
             0/1,  3/{N-1},  4/{N}
}{
        node[mybox] (bck) at ($(-k*d, 0)$) {$S_{s}$};
}

end{tikzpicture}
end{document}