# 「NOI2016」区间

## #题面

### #输入输出样例

6 3
3 5
1 2
3 4
2 2
1 5
1 4


2


### #数据范围与提示

1 $20$ $9$ $0 \le l_i \le r_i \le 100$
2 $10$
3 $199$ $3$ $0 \le l_i \le r_i \le 100000$
4 $200$
5 $1000$ $2$
6 $2000$
7 $199$ $60$ $0 \le l_i \le r_i \le 5000$
8 $200$ $50$
9 $0 \le l_i \le r_i \le 10^9$
10 $1999$ $500$ $0 \le l_i \le r_i \le 5000$
11 $2000$ $400$
12 $500$ $0 \le l_i \le r_i \le 10^9$
13 $30000$ $2000$ $0 \le l_i \le r_i \le 100000$
14 $40000$ $1000$
15 $50000$ $15000$
16 $100000$ $20000$
17 $200000$ $0 \le l_i \le r_i \le 10^9$
18 $300000$ $50000$
19 $400000$ $90000$
20 $500000$ $200000$