Problem7524--[CSES Problem Set] Tasks and Deadlines

7524: [CSES Problem Set] Tasks and Deadlines

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Time Limit : 1.000 sec  Memory Limit : 256 MiB

Description

You have to process $n$ tasks. Each task has a duration and a deadline, and you will process the tasks in some order one after another. 
Your reward for a task is $d-f$ where $d$ is its deadline and $f$ is your finishing time. (The starting time is $0$, and you have to process all tasks even if a task would yield negative reward.)
What is your maximum reward if you act optimally?

Input

The first input line has an integer $n$: the number of tasks.
After this, there are nn lines that describe the tasks. Each line has two integers $a$ and $d$: the duration and deadline of the task.

Output

Print one integer: the maximum reward.

Constraints

$1≤n≤2⋅10^5$
$1 \le a,d \le 10^6$

Sample 1 Input

3
6 10
8 15
5 12

Sample 1 Output

2

HINT

相同问题:CSES 1630

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