Minimum Number of Platforms

You are given two lists of time stamps representing the arrivals and departures of trains at a station. Each time stamp is in the format HH:MM (24-hour clock). Your task is to calculate the minimum number of platforms required so that no train has to wait.

The conversion from a time string to minutes past midnight can be expressed as:

Note: You must read input from stdin and write the result to stdout.

inputFormat

The input consists of three lines:

1. An integer n representing the number of trains.
2. n space-separated strings representing the arrival times.
3. n space-separated strings representing the departure times.

outputFormat

Output a single integer which is the minimum number of platforms required so that no train waits.

5
09:00 09:20 09:25 09:40 10:00
09:10 09:30 09:35 09:50 10:10

2