\documentclass{standalone}

\usepackage{tikz}
\usepackage{shapes}

\begin{document}
\begin{tikzpicture}
  \grid{10}{10}{(-1,-1)}

  \staircaseV{blue}{(0,0)}
  \staircaseV{green}{(3,4)}
  
  \square{lightgray}{(3,3)}
  \square{lightgray}{(4,3)}

  \square{gray}{(1,4)}
  \square{gray}{(2,3)}
  \square{gray}{(2,4)}
  \square{gray}{(3,2)}
  \square{gray}{(4,1)}
  \square{gray}{(4,2)}

\end{tikzpicture}
\end{document}