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: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>

#define rep(i, l, r) for (int i = l; i < r; i++)
#define MAX 100001

int main(void) {
  int N, M, Q;
  scanf("%d %d %d", &N, &M, &Q);
  int line[501][501] = {0}; // line[都市L][都市R]:列車(線路)が通っている本数
  int L, R;
  int p[100001], q[100001];
  rep(i, 0, M) {
    scanf("%d %d", &L, &R);
    line[L][R]++;
  }
  rep(i, 0, Q) scanf("%d %d", &p[i], &q[i]);

  int train[502][502] = {0}; // train[都市L][都市R]:完全に含まれる列車の本数
  for (int s = N; s > 0; s--) {
    for (int g = s; g <= N; g++) {
      train[s][g] += line[s][g] + train[s][g - 1] + train[s + 1][g];
    }
  }

  rep(i, 0, Q) {
    printf("%d\n", train[p[i]][q[i]]);
  }
  return 0;
}