How many times did Michael Schumacher won from races hosted in Sepang International Circuit?
win from races refers to max(points)
SELECT SUM(T2.wins) FROM drivers AS T1 INNER JOIN driverStandings AS T2 ON T2.driverId = T1.driverId INNER JOIN races AS T3 ON T3.raceId = T2.raceId INNER JOIN circuits AS T4 ON T4.circuitId = T3.circuitId WHERE T1.forename = 'Michael' AND T1.surname = 'Schumacher' AND T4.name = 'Sepang International Circuit'