CREATE TABLE table_15088557_1 (stage INTEGER, winner VARCHAR)
SELECT MIN(stage) FROM table_15088557_1 WHERE winner = "Sergei Smetanine"
สเตจขั้นต่ำที่ Sergei Smetanine ชนะคือเท่าไร?
What is the minimum stage where Sergei Smetanine won?