Size of front hard brake line nut?


Little engine that could
Not sure if I described that correctly. I cant seem to remove the drivers side front brake nut where it connects to the soft line in the wheelwell. Maybe its 7/16 or 9/16, I tried using vise grips, but it starting to round out. Worked on the pass side, but this ones a pain. Anyone know the size so I can buy the flare wrench?