get the node id by the relation id?

khourge · 2018-01-06T09:46:06.000Z

Hi everyone,
how can i get the node id by the relation id?
for exemple i search node id of Communauté de Madrid
http://www.openstreetmap.org/relation/349055

user_5359 · 2018-01-06T13:15:34.000Z

http://www.openstreetmap.org/node/21068295

Which tool do you use?