Maximum Non-Overlapping Events

You are given a list of events, where each event is represented by its start time and end time. Your task is to determine the maximum number of non-overlapping events that can be scheduled.

An event is defined as an interval $(s, e)$ where $s$ is the start time and $e$ is the end time. Two events $(s_1, e_1)$ and $(s_2, e_2)$ are non-overlapping if and only if $s_2 \ge e_1$.

You may consider using a greedy algorithm that sorts the events by their end times to achieve an optimal solution.

inputFormat

The first line contains an integer $n$ representing the number of events. Each of the following $n$ lines contains two integers separated by a space, representing the start time and end time of an event.

outputFormat

Output a single integer representing the maximum number of non-overlapping events that can be scheduled.## sample

5
1 5
2 6
1 3
3 4
5 7

3