CREATE TABLE table_18920 ("Country" TEXT, "Currency name" TEXT, "Month with highest inflation rate" TEXT, "Highest monthly inflation rate" TEXT, "Equivalent daily inflation rate" TEXT, "Time required for prices to double" TEXT)

what's the country with highest monthly inflation rate being 3.13 10 8 %
SELECT "Country" FROM table_18920 WHERE "Highest monthly inflation rate" = '3.13 × 10 8 %'
SELECT "Country" FROM "table_18920" WHERE "Highest monthly inflation rate" = '3.13 × 10 8 %'