CREATE TABLE table_name_8 (year INT, venue VARCHAR, event VARCHAR, result VARCHAR)

What is earliest year that had a 50km event with a 2nd place result played in London, United Kingdom?
SELECT MIN(year) FROM table_name_8 WHERE event = "50km" AND result = "2nd" AND venue = "london, united kingdom"
SELECT MIN("year") FROM "table_name_8" WHERE "2nd" = "result" AND "50km" = "event" AND "london, united kingdom" = "venue"