Maximize events attended given date ranges

You are given n events, where each event i can be attended on any single day within an inclusive range $[start_i, end_i]$. You can attend at most one event per day, and attending an event consumes exactly one day.

Return the maximum number of events you can attend.

Input

• An array events of length n , where events[i] = [start_i, end_i] .

Output

• An integer: the maximum number of events that can be attended.

Constraints (typical)

• 1 <= n <= 1e5
• 1 <= start_i <= end_i <= 1e5 (or up to ~ 1e9 in some variants)

Example

• Input: [[1,2],[2,3],[3,4]]
• Output: 3
• Explanation: Attend the first on day 1, second on day 2, third on day 3.