I'm not up on the current staffing levels but I think last I heard it was 2F, 4C, and 5Y for a full load. That's for (depending on the configuration) 12 F seats, 49 C, and I forget what is in Y now -- used to be 225 but I think it is around 180-something now what with the F suites and expanded C pitch and Economy Plus taking up more room.
I am not sure if the Purser is included in that staffing count somewhere these days, or is on top of that. (At various times in the past it was 3F, 5C, and 6Y, plus a Purser.) On international widebodies, UA's staffing guidelines are always well above FAA mins.
Hopefully a currently active UA F/A can chime in -- I'm just going form memory and would hate to give out wrong info!