CREATE TABLE table_31372 ("Country with flag" TEXT, "Area  ( km\\u00b2 ) " FLOAT, "Population  ( 1 July 2005 est. ) " FLOAT, "Population density  ( per km\\u00b2 ) " TEXT, "Capital" TEXT)

What is the highest value of area when capital is San Juan?
SELECT MAX("Area (km\u00b2)") FROM table_31372 WHERE "Capital" = 'San Juan'
SELECT MAX("Area (km\u00b2)") FROM "table_31372" WHERE "Capital" = 'San Juan'