Workshop Scheduling

Medium#greedy #sorting #intervals· solved by 0 · time limit 2.0 s

UPEEC has $n$ workshop slots, each with a start and end time, but only one hall. A workshop can start exactly when the previous one ends. What is the maximum number of workshops you can hold?

Input

$n$ , then $n$ lines start end (start < end).

Output

The maximum number of workshops.

Constraints

$1 \le n \le 10^5$

Sample 1

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Output

Sample 2

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Output