500 mL of 1.2 M KI solution is mixed with 500 mL of $0.2 \mathrm{MKMnO}_4$ solution in basic medium. The liberated iodine was titrated with standard $0.1 \mathrm{M} \mathrm{Na}_2 \mathrm{~S}_2 \mathrm{O}_3$ solution in the presence of starch indicator till the blue color disappeared. The volume (in L ) of $\mathrm{Na}_2 \mathrm{~S}_2 \mathrm{O}_3$ consumed is ... (Nearest integer)