A man leave for his office from his house. After moving distance of 20 km, he turn south and walked 10 km then he turn his right and after walking further 35 km, again turned his right and move for 10 km, and at last he turned his right and walked 5 km to reach his office. He is facing east direction now. If straight distance between his house and office is 30 km, then he started walking in which direction before his first south turn?