Helpdesk Session Duration Ledger

A helpdesk's ticketing system logs every time an agent logs in and later logs out; an agent may log in and out several times across a single day. Each log line records an agent's id, the day, and the login and logout minute of one session on that day. Build a ledger showing, for every agent and day that appears in the log, the total number of minutes that agent was logged in that day (the sum of logout - login over all of that agent's sessions on that day).

Input format

Line 1: an integer n, the number of session records. Each of the next n lines contains four integers empId day inTime outTime — one login session, where inTime < outTime.

Output format

For every distinct (empId, day) pair that appears in the log, print one line empId day totalMinutes, where totalMinutes is the sum of outTime - inTime over all sessions with that exact empId and day. Print the lines ordered by empId ascending, breaking ties by day ascending.

Constraints

• 1 <= n <= 1000
• 1 <= empId <= 100000
• 1 <= day <= 100000
• 0 <= inTime < outTime <= 1440

4
1 1 480 540
1 1 600 650
2 1 400 430
1 2 500 560

1 1 110
1 2 60
2 1 30

1
5 3 100 160

5 3 60