One. They put in about 2 MJ and got back 3 MJ, and the laser input energy was about 400 MJ. With 20% efficient lasers, you only need 10MJ into the lasers to get 2MJ in the laser beam. So a factor of five for breakeven.

If you're generating electricity, you've also got a factor of 3 for the heat cycle loss, so a 15X gain for engineering breakeven.

The pulse repetition rate is also due to the obsolete lasers. Modern petawatt lasers can do better than one hertz and are still improving (see my first link above).