A 60 y.o. patient cpmplains of weakness, dizziness, heaviness in the upper part of abdomen, paresthesia of toes and fingers. Objectively: skin icteri-tiousness, tongue is crimson, smooth. Hepatomegaly. In blood: Hb- 90 g/l, erythrocytes - 2, 3 ■ 1012/l, reticulocytes - 0,2%; color index - 1,2, macrocytosis; Jolly's bodies, Cabot's ring bodies. What medication is the most appropriate for treatment?