CREATE TABLE table_204_312 (id DECIMAL, "stage" TEXT, "date" TEXT, "route" TEXT, "terrain" TEXT, "length" TEXT, "winner" TEXT)

paul wellens won stage 13 . who won the next stage ?
SELECT "winner" FROM table_204_312 WHERE "stage" = 13 + 1
SELECT "winner" FROM "table_204_312" WHERE "stage" = 14