Problem2015--noip2017 跳房子

2015: noip2017 跳房子

Time Limit: 2 Sec  Memory Limit: 128 MB
Submit: 5  Solved: 1
[Status] [Submit] [Creator:]

Description

Sample Input Copy 

7 4 10
2 6
5 -3
10 3
11 -3
13 1
17 6
20 2

Sample Output Copy 

2

HINT

Source/Category

noip noip2017 noip普及组 
[Submit] [Status]