CREATE TABLE table_43929 ("Sport" TEXT, "Gold" FLOAT, "Silver" FLOAT, "Bronze" FLOAT, "Total" FLOAT)

What is the smallest number of silvers associated with bronzes under 20, totals of 1, golds of 0, and in Water Polo?
SELECT MIN("Silver") FROM table_43929 WHERE "Bronze" < '20' AND "Total" = '1' AND "Sport" = 'water polo' AND "Gold" < '0'
SELECT MIN("Silver") FROM "table_43929" WHERE "Bronze" < '20' AND "Gold" < '0' AND "Sport" = 'water polo' AND "Total" = '1'