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 <cstdio>
#include <cstring>
#include <vector>
#include <set>
#include <unordered_set>
#include <cmath>
#include <algorithm>
#include <numeric>
#include <cassert>
#include <utility>

using namespace std;
using lli = long long int;
// #define DEBUG
#ifdef DEBUG
#define debug(var) cout << (#var) << ": " << (var) << endl;
template<class T> void dump_array_impl(const T& a) {
  bool first = true;
  for (auto&& x : a) {
    if (!first) cout << ", "; else first = false;
    cout << x;
  }
}
#define debug_array(a) cout<<(#a)<<": ";dump_array_impl(a);cout<<endl
#else
#define debug(var) {}
#define debug_array(a) {}
#endif
template<class T> void read_n(vector<T>& v, size_t n) {
  v = vector<T>(n); for (lli i=0; i<n; ++i) cin >> v[i];
}
template<class T> T gabs(const T& x) { return max(x, -x); }
#define abs gabs

int n, m, q;
int mat[501][501];
int main() {
  memset(mat, 0, sizeof(decltype(mat[0][0]))*501*501);
  cin >> n >> m >> q;
  for (int i=0; i<m; ++i) {
    int a, b; cin >> a >> b;
    mat[b][a]++;
  }
  for (int y=2; y<=n; ++y) {
    for (int i=1, j=y; j<=n; ++i, ++j) {
      mat[j][i] += mat[j-1][i] + mat[j][i+1] - mat[j-1][i+1];
    }
  }
  for (int i=0; i<q; ++i) {
    int a, b;
    cin >> a >> b;
    cout << mat[b][a] << endl;
  }
  return 0;
}