\begin{Schunk}
\begin{Sinput}
 datX
\end{Sinput}
\begin{Soutput}
   ID cars      fear
1 111    6  90.61873
2 112    5  97.35806
3  NA    7  91.15475
4 114    6  94.99807
5 115    5 106.76902
6 116    5 114.09072
7  NA    9 109.50524
\end{Soutput}
\begin{Sinput}
 datY
\end{Sinput}
\begin{Soutput}
   ID pets
1 111    5
2  NA    4
3 113    4
4 114    8
5 115    6
6  NA    4
7 117    7
\end{Soutput}
\end{Schunk}
