Problem:
Score: 400 points

Problem Statement

In Takahashi Kingdom, there is a east-west railroad and N cities along it, numbered 1, 2, 3, ..., N from west to east.
A company called AtCoder Express possesses M trains, and the train i runs from City L_i to City R_i (it is possible that L_i = R_i).
Takahashi the king is interested in the following Q matters:

The number of the trains that runs strictly within the section from City p_i to City q_i, that is, the number of trains j such that p_i \leq L_j and R_j \leq q_i.

Although he is genius, this is too much data to process by himself. Find the answer for each of these Q queries to help him.

Constraints

N is an integer between 1 and 500 (inclusive).

M is an integer between 1 and 200 \ 000 (inclusive).

Q is an integer between 1 and 100 \ 000 (inclusive).

1 \leq L_i \leq R_i \leq N (1 \leq i \leq M)

1 \leq p_i \leq q_i \leq N (1 \leq i \leq Q)

Input

Input is given from Standard Input in the following format:

N M Q
L_1 R_1
L_2 R_2
:
L_M R_M
p_1 q_1
p_2 q_2
:
p_Q q_Q

Output

Print Q lines. The i-th line should contain the number of the trains that runs strictly within the section from City p_i to City q_i.

Sample Input 1

2 3 1
1 1
1 2
2 2
1 2

Sample Output 1

3

As all the trains runs within the section from City 1 to City 2, the answer to the only query is 3.

Sample Input 2

10 3 2
1 5
2 8
7 10
1 7
3 10

Sample Output 2

1
1

The first query is on the section from City 1 to 7. There is only one train that runs strictly within that section: Train 1.
The second query is on the section from City 3 to 10. There is only one train that runs strictly within that section: Train 3.

Sample Input 3

10 10 10
1 6
2 9
4 5
4 7
4 7
5 8
6 6
6 7
7 9
10 10
1 8
1 9
1 10
2 8
2 9
2 10
3 8
3 9
3 10
1 10

Sample Output 3

7
9
10
6
8
9
6
7
8
10

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;

const int MAXN = 510;
int bit[MAXN], n;
void add(int p, int val) {
	for (; p<=n; p+=p&-p)
		bit[p]+=val;
}
int sum(int p) {
	int ans=0;
	for (; p>0; p-=p&-p)
		ans += bit[p];
	return ans;
}
struct Line {
	int l,r;
	int id;
	bool operator<(const Line& rhs) const {
		return l<rhs.l;
	}
}line[200010], query[200010];
int main() {
	int m,q;
	cin>>n>>m>>q;
	for (int i=0; i<m; i++)
		cin>>line[i].l>>line[i].r;
	for (int i=0; i<q; i++) {
		cin>>query[i].l>>query[i].r;
		query[i].id = i;
	}
	sort(line, line+m);
	sort(query, query+q);

	int ans[200010];
	for (int i=0; i<m; i++)
		add(line[i].r, 1);
	for (int i=0, starter=0; i<q; i++) {
		while(starter<m && line[starter].l<query[i].l)
			add(line[starter++].r, -1);
		// cout<<"query="<<query[i].id<<"  starter="<<starter<<endl;
		ans[query[i].id] = sum(query[i].r);
	}

	for (int i=0; i<q; i++)
		cout<<ans[i]<<endl;
	return 0;
}