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>
#include <limits.h>

main()
{
  int N, M, Q;
  int *L, *R,*p,*q,*s;
  int **c,**x;
  int i, k, j;
  scanf("%d %d %d",&N,&M,&Q);

  L = (int*)malloc(sizeof (int)*M);
  R = (int*)malloc(sizeof (int)*M);
  p = (int*)malloc(sizeof (int)*Q);
  q = (int*)malloc(sizeof (int)*Q);
  s = (int*)malloc(sizeof (int)*Q);
  c = (int**)malloc(sizeof (int*)*N);
  for(i=0; i<N; i++)
    c[i] = (int*)malloc(sizeof (int)*N);
  x = (int**)malloc(sizeof (int*)*N);
  for(i=0; i<N; i++)
    x[i] = (int*)malloc(sizeof (int)*N);

  for(i=0; i<M; i++)
    scanf("%d %d",&L[i], &R[i]);
  for(i=0; i<Q; i++)
    scanf("%d %d",&p[i], &q[i]);
  for(i=0; i<N; i++)
    for(k=0; k<N; k++)
      {
        x[i][k] = 0;
        c[i][k] = 0;
      }

  for(i=0; i<M; i++)
    x[L[i]-1][R[i]-1]++;

  for(i=0; i<N; i++)
    for(j=0; j<N; j++)
      for(k=0; k<=j; k++)
        c[i][j] = c[i][j] + x[i][k];

  for(i=0; i<Q; i++)
    {
      s[i]=0;
      for(k=p[i]; k<=q[i]; k++)
        if(k!=1)
          s[i] = s[i] + (c[k-1][q[i]-1] - c[k-1][p[i]-2]);
        else
          s[i] = s[i] + c[k-1][q[i]-1];
      printf("%d\n",s[i]);
    }

  return 0;
}