The command issued to randomly select 20 istances per domain is

./select-all-instances.bash 13152024460108 20 suite-official

where suite-official contains one subdirectory for each domain containing the corresponding instances

The seed 13152024460108 is the concatenation of the winning numbers of the Euromillion lottery of Tuesday 22nd April 2014
http://www.euro-millions.com/results.asp 

In case you need to re-build the selector program:

g++ instance-selector.cpp -o instance-selector
