Example of the algorithmicx package.

algorithmic.tex

\documentclass[12pt]{article}

\usepackage[czech]{babel}
\usepackage{geometry}
\usepackage{lipsum}

\usepackage{algorithmicx}
\usepackage{algpseudocode}
\usepackage{algorithm}

\pagenumbering{gobble}

\begin{document}

\begin{algorithmic}
\If {$i\geq maxval$}
    \State $i\gets 0$
\Else
    \If {$i+k\leq maxval$}
        \State $i\gets i+k$
    \EndIf
\EndIf
\end{algorithmic}

\end{document}