แสดงชื่อละครเพลงที่มีนักแสดงอย่างน้อยสามคน
Show names of musicals which have at least three actors.
df_actor = pd.DataFrame(columns = ['Musical_ID']); df_musical = pd.DataFrame(columns = ['Name', 'Musical_ID'])
df_musical[df_musical['Musical_ID'].isin(df_actor['Musical_ID'].value_counts()[df_actor['Musical_ID'].value_counts()>=3].index)]['Name']