521. Maximum Number of Events That Can Be Attended

Given events as [startDay, endDay] pairs, you can attend one event per day, on any day between its start and end inclusive. Return the maximum number of events you can attend. The input is a JSON array of [startDay, endDay] pairs.

Input: A JSON array of [startDay, endDay] pairs.

Output: Integer — the maximum events attended.

Examples

Input: [[1,2],[2,3],[3,4],[1,2]]
Output: 4
Explanation: Attend all four on distinct days.

Input: [[1,2],[2,3],[3,4]]
Output: 3
Explanation: One per day.

Input: [[1,1]]
Output: 1
Explanation: Single event.

Constraints

• 1<=n<=10^5
• 1<=start<=end<=10^5

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