4828: P1220 关路灯

Memory Limit：128 MB Time Limit：1.000 S
Judge Style：Text Compare Creator：
Submit：0 Solved：0

Description

Input

Output

Sample Input Copy 

5 3
2 10
3 20
5 20
6 30
8 10

Sample Output Copy 

270

HINT

Source/Category

SubmitSubmit RecordStatisticsShowOff!