read n k
a=(`tr ' ' '\n' | sort -nr`)
if((a[0]<0))
then
    echo ${a[0]}
else
    a=(`echo ${a[@]} | sed -r "s/\-[0-9]+//g" | tr ' ' '\n' | sort -nr | head -$k`)
    echo $((`echo ${a[@]} | tr ' ' '+'`))
fi