Mrs. Delgаdо is а 68-yeаr-оld wоman admitted to the med-surg unit with a diagnosis of severe pneumococcal pneumonia. Her PCP orders Penicillin G Potassium 2,000,000 IV Piggyback (IVPB) every 4 hours. After reconstituting to a concentration of 1,000,000 units/mL, how many milliliters (mLs) will you withdraw from the vial to prepare Mrs. Delgado's dose? Enter the number only.