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 (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>
int l[200010],r[200010],idx[200010];
int ql[200010],qr[200010],qidx[200010];
int ans[200010];
int sum[510];
int cmp(const void*p,const void*q){
	if(r[*(int*)p]>r[*(int*)q])return 1;
	return -1;
}
int cmpq(const void*p,const void*q){
	if(qr[*(int*)p]>qr[*(int*)q])return 1;
	return -1;
}
int main(){
	int n,m,q;
	scanf("%d%d%d",&n,&m,&q);
	for(int i=0;i<m;i++){
		scanf("%d%d",l+i,r+i);
		idx[i]=i;
	}
	qsort(idx,m,sizeof(int),cmp);
	for(int i=0;i<q;i++){
		scanf("%d%d",ql+i,qr+i);
		qidx[i]=i;
	}
	qsort(qidx,q,sizeof(int),cmpq);
	
	int crr=0;
	for(int ii=0;ii<q;ii++){
		int i=qidx[ii];
		while(crr<m&&r[idx[crr]]<=qr[i])sum[l[idx[crr++]]]++;
		ans[i]=crr;
		for(int j=0;j<ql[i];j++)ans[i]-=sum[j];
	}
	for(int i=0;i<q;i++)printf("%d\n",ans[i]);
}