Jack Link's beef stick & cheese, sasquatch size. You're going to need at least 6 per day to get over 1600 calories but it's going to be nearly 3x recommended sodium for the day so be sure to drink lots of water.
If you manage to poop at any time during those three days you deserve a medal.
You risk Kidney stones with that Sodium. I don't know what toilet horrors you and your butthole face that have driven you to this point, but heed my warning, kidney stones really fucking hurt.