Passage: May, 19th, 2010London, Great Britain. World premiere of 3 DV channel. GS Group and Valery Gergiev presented joint 3D-project at the press-conference in Barbican-centre, London. General Satellite Corporation announced the launch of its own European 3D TV channel 3DV which will be filled with different content, including the one dedicated to culture and travelling. Considerable part of channel’s programs will be the Mariinsky Theatre programs. Fragments from the Mariinsky Theatre Gala Concert and Giselle ballet staged at the Mariinsky Theatre were presented in 3D during presentation before press-conference.

Question: How many DV channels premiered in May 2010?
3