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 Java8 (OpenJDK 1.8.0) (judge verdict: Time Limit Exceeded)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.*;

public class Main {
  private static class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner(InputStream in) {
      reader = new BufferedReader(new InputStreamReader(in));
      tokenizer = null;
    }

    public String next() {
      if (tokenizer == null || !tokenizer.hasMoreTokens()) {
        try {
          tokenizer = new StringTokenizer(reader.readLine());
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }
      return tokenizer.nextToken();
    }

    public String nextLine() {
      if (tokenizer == null || !tokenizer.hasMoreTokens()) {
        try {
          return reader.readLine();
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }

      return tokenizer.nextToken("\n");
    }

    public long nextLong() {
      return Long.parseLong(next());
    }

    public int nextInt() {
      return Integer.parseInt(next());
    }

    public double nextDouble() {
      return Double.parseDouble(next());
    }

    public int[] nextIntArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++)
        a[i] = nextInt();
      return a;
    }

    public long[] nextLongArray(int n) {
      long[] a = new long[n];
      for (int i = 0; i < n; i++)
        a[i] = nextLong();
      return a;
    }
  }

  private static Set<Integer> getMoreThanMin(int min, List<int[]> trains, List<Integer> trainIndex) {
    Set<Integer> index = new HashSet<>();
    if (min <= trains.get(0)[0]) {
      index.addAll(trainIndex);
    } else if (trains.get(trains.size() - 1)[0] >= min) {
      int left = -1;
      int right = trains.size() - 1;
      while (right - left > 1) {
        int center = left + (right - left) / 2;
        if (trains.get(center)[0] >= min) right = center;
        else left = center;
      }
      index.addAll(trainIndex.subList(right, trains.size()));
    }
    return index;
  }

  private static Set<Integer> getLessThanMax(int max, List<int[]> trains, List<Integer> trainIndex) {
    Set<Integer> index = new HashSet<>();
    if (trains.get(trains.size() - 1)[1] <= max) {
      index.addAll(trainIndex);
    } else if (trains.get(0)[1] <= max) {
      int left = 0;
      int right = trains.size();
      while (right - left > 1) {
        int center = left + (right - left) / 2;
        if (trains.get(center)[1] <= max) left = center;
        else right = center;
      }
      index.addAll(trainIndex.subList(0, left + 1));
    }
    return index;
  }

  public static void main(String[] args) {
    FastScanner sc = new FastScanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int q = sc.nextInt();
    int[][] lr = new int[m][3];
    int[][] pq = new int[q][2];
    for (int i = 0; i < m; i++) {
      lr[i][0] = sc.nextInt();
      lr[i][1] = sc.nextInt();
      lr[i][2] = i;
    }
    for (int i = 0; i < q; i++) {
      pq[i] = sc.nextIntArray(2);
    }
    List<int[]> l = new ArrayList<>();
    List<int[]> r = new ArrayList<>();
    for (int[] train : lr) {
      l.add(train);
      r.add(train);
    }
    Collections.sort(l, (int[] a, int[] b) -> a[0] - b[0]);
    Collections.sort(r, (int[] a, int[] b) -> a[1] - b[1]);
    List<Integer> lindex = new ArrayList<>();
    List<Integer> rindex = new ArrayList<>();
    for (int i = 0; i < m; i++) lindex.add(l.get(i)[2]);
    for (int i = 0; i < m; i++) rindex.add(r.get(i)[2]);
    for (int i = 0; i < q; i++) {
      int min = pq[i][0];
      int max = pq[i][1];
      Set<Integer> moreThanMin = getMoreThanMin(min, l, lindex);
      Set<Integer> lessThanMax = getLessThanMax(max, r, rindex);
      moreThanMin.retainAll(lessThanMax);
      System.out.println(moreThanMin.size());
    }
  }
}