Among all the tweets with a positive sentiment, how many of them were posted by male users in Australia?
tweet with positive sentiment refers to Sentiment > 0; male user refers to Gender = 'Male'; 'Australia' is the Country
SELECT COUNT(T1.TweetID) FROM twitter AS T1 INNER JOIN location AS T2 ON T2.LocationID = T1.LocationID INNER JOIN user AS T3 ON T3.UserID = T1.UserID WHERE T2.Country = 'Australia' AND T3.Gender = 'Male' AND T1.Sentiment > 0