documentclass{article}
usepackage[utf8]{inputenc}

usepackage[latin1]{inputenc}
usepackage{tikz}
usetikzlibrary{shapes,arrows}

% Define block styles
tikzstyle{block} = [rectangle, draw,
    text width=15em, text centered, rounded corners, minimum height=16em]
tikzstyle{line} = [draw, -latex']
tikzstyle{cloud} = [draw, ellipse, node distance=6cm,
    minimum height=8em]

begin{document}

begin{tikzpicture}[node distance = 10cm, auto]
    % Place nodes
    node [block] (init) {underline{Machine}};
    node [cloud, left of=init] (data) {underline{Training data set}};
    node [cloud, above right of=init] (input) {underline{Input}};
    node [cloud, below right of=init] (output) {underline{Output}};
    % Draw edges
    path [line] (data) -- (init);
    path [line] (input) -- (init);
    path [line] (init) -- (output);
end{tikzpicture}


end{document}