1. Description

Create a music playlist manager. Input operation commands to manage playlist. Initial list is empty. Supported operations:

• add song_name duration(s) artist：Add song (duplicates by name not allowed)
• play [N]：Play Nth song (play first if no number, remove after playing)
• list：Show all songs (format: No.song_name(artist)-duration)
• remove artist：Remove all songs by artist Output "Operation failed" for invalid commands

2. Input & Output

Input:

• Multiple commands separated by semicolons

commands = input().split(';')

Output:

• Output results per command (play outputs "Now playing: song", list outputs multiple lines)

Example

# Input: 
add Nightwish 360 Floor;add Nemo 240 Floor;list
# 输出: 
1.Nightwish(Floor)-360秒
2.Nemo(Floor)-240秒

# Input: 
add Hello 300 Adele;play;play 2
# 输出: 
Now playing: Hello
Operation failed