pacman -Sl system | cut -d" " -f2 | xargs pacman -Si | grep -i "installed size" | cut -d: -f2 | awk -F'\t' 'BEGIN{ s["MiB"]=1024; s["KiB"]=1;} {split($1, a, " "); print a[1] * s[a[2]], "KiB", $1}' | cut -d" " -f1 | paste -sd+ - | bc