Meeting Scheduler System

Develop a meeting scheduling system that manages meetings by reading commands from standard input and printing results to standard output. The system is required to handle the following functionalities:

• Schedule a new meeting
• Update details of an existing meeting
• Cancel a meeting
• Send reminders to meeting participants

When scheduling or updating a meeting, the system must check the following conditions:

• If a meeting with identifier \( id \) already exists, then the command should return Meeting ID already exists.
• If a meeting does not exist when updating, canceling, or sending reminders, then the command should return Meeting ID does not exist.
• Otherwise, the commands should return appropriate success messages.

Example:

Input:
5
SCHEDULE 1 10am Alice,Bob
SCHEDULE 1 11am Alice,Bob
UPDATE 1 11am
REMINDER 1
CANCEL 1

Output:
Meeting scheduled successfully.
Meeting ID already exists.
Meeting updated successfully.
Reminder sent successfully.
Meeting cancelled successfully.

Note: All commands are read from stdin and the results are printed to stdout, one per line.

inputFormat

The first line of input contains an integer \( T \) representing the number of commands. Each of the following \( T \) lines contains a command in one of the following formats:

• SCHEDULE meeting_id time_slot participants (participants are provided as a comma-separated list without spaces)
• UPDATE meeting_id new_time_slot
• CANCEL meeting_id
• REMINDER meeting_id

outputFormat

For each command, output the corresponding result message on a new line. The messages can be one of the following:

• Meeting scheduled successfully.
• Meeting ID already exists.
• Meeting updated successfully.
• Meeting ID does not exist.
• Meeting cancelled successfully.
• Reminder sent successfully.

## sample

5
SCHEDULE 1 10am Alice,Bob
SCHEDULE 1 11am Alice,Bob
UPDATE 1 11am
REMINDER 1
CANCEL 1

Meeting scheduled successfully.
Meeting ID already exists.
Meeting updated successfully.
Reminder sent successfully.
Meeting cancelled successfully.

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