Calculate Customer Interaction Times

You are given a series of events related to customer interactions. Each event is represented by a tuple consisting of a customer ID, an event type (either start or end), and a timestamp. An interaction starts with a start event and ends with the corresponding end event. The interaction time for one session is calculated as:

[ T = \text{timestamp}{\text{end}} - \text{timestamp}{\text{start}} ]

A customer may have multiple interactions. Your task is to compute the total interaction time for each customer by summing all of their interaction durations. The final output should list each customer ID along with their total interaction time, sorted by customer ID in ascending order.

Note: It is possible that an end event might occur with a timestamp earlier than its corresponding start event, which could result in a negative duration. In such cases, use the computed negative value.

inputFormat

The input is given via standard input (stdin) with the following format:

• The first line contains an integer n representing the number of events.
• The following n lines each contain an event in the format: customer_id event_type timestamp, where customer_id and timestamp are integers and event_type is a string that can be either start or end.

outputFormat

For each customer, print a line containing the customer ID and the total interaction time separated by a space. The output should be in ascending order of customer ID. The result is printed to standard output (stdout).

Example:

Input:
6
1 start 100
2 start 150
1 end 200
1 start 300
1 end 400
2 end 250
Output:
1 200
2 100

## sample</p>

2
1 start 100
1 end 200

1 100

</p>