สโมสรใดมีสมาชิกวิชาเอก "600" มากที่สุด?
Which club has the most members majoring in "600"?
student = pd.DataFrame(columns=['stuid', 'major']); member_of_club = pd.DataFrame(columns=['clubid', 'stuid']); club = pd.DataFrame(columns=['clubname', 'clubid'])
club.loc[member_of_club[member_of_club['stuid'].isin(student[student['major'] == '600']['stuid'])]['clubid'].value_counts().idxmax()]['clubname']