CREATE TABLE table_2704 ("Constituency" TEXT, "Winner" TEXT, "Party" TEXT, "Margin" FLOAT, "Runner-up a" TEXT, "Party a" TEXT)

who ended runner-up to sankar adhi?
SELECT "Runner-up a" FROM table_2704 WHERE "Winner" = 'Sankar Adhi'
SELECT "Runner-up a" FROM "table_2704" WHERE "Winner" = 'Sankar Adhi'