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: Accepted)


import java.util.Arrays;
class SegmentTreeRSQ {
  public int M, H, N;
  public long[] st;
  public long[] plus;
  
  public SegmentTreeRSQ(int n)
  {
      N = n;
      M = Integer.highestOneBit(Math.max(N-1, 1))<<2;
      H = M>>>1;
      st = new long[M];
      plus = new long[H];
  }
  
  public SegmentTreeRSQ(int[] a)
  {
      N = a.length;
      M = Integer.highestOneBit(Math.max(N-1, 1))<<2;
      H = M>>>1;
      st = new long[M];
      plus = new long[H];
      for(int i = 0;i < N;i++){
          st[H+i] = a[i];
      }
      for(int i = (M>>1)-1;i >= 1;i--){
          propagate(i);
      }
  }
  
  public void add(int pos, int v)
  {
      for(int i = H+pos;i >= 1;i >>>= 1){
          st[i] += v;
      }
  }
  
  private void propagate(int i)
  {
      int count = H/Integer.highestOneBit(i);
      st[i] = st[2*i]+st[2*i+1]+plus[i]*count;
  }
  
  public void add(int l, int r, int v) { if(l < r)add(l, r, v, 0, H, 1); }
  
  private void add(int l, int r, int v, int cl, int cr, int cur)
  {
      if(cur >= H){
          st[cur] += v;
      }else if(l <= cl && cr <= r){
          plus[cur] += v;
          propagate(cur);
      }else{
          int mid = cl+cr>>>1;
          if(cl < r && l < mid){
              add(l, r, v, cl, mid, 2*cur);
          }
          if(mid < r && l < cr){
              add(l, r, v, mid, cr, 2*cur+1);
          }
          propagate(cur);
      }
  }
  
  private long gsum;
  
  public long sum(int l, int r) { 
      gsum = 0;
      sum(l, r, 0, H, 1);
      return gsum;
  }
  
  private void sum(int l, int r, int cl, int cr, int cur)
  {
      if(l <= cl && cr <= r){
          gsum += st[cur];
      }else{
          int mid = cl+cr>>>1;
          if(cl < r && l < mid){
              sum(l, r, cl, mid, 2*cur);
          }
          if(mid < r && l < cr){
              sum(l, r, mid, cr, 2*cur+1);
          }
          gsum += plus[cur]*(Math.min(r,cr)-Math.max(l,cl));
      }
  }
}



public class Main {


  private static void solve() {
    int n = ni();
    int m = ni();
    int q = ni();
    

    int[][] line = new int[m][2];
    for (int i = 0; i < m; i ++) {
      line[i][0] = ni() - 1;
      line[i][1] = ni() - 1;
    }
    Arrays.sort(line, (o1, o2) -> o1[1] - o2[1]);

    int[][] query = new int[q][4];
    for (int i = 0; i < q; i ++) {
      query[i][0] = ni() - 1;
      query[i][1] = ni() - 1;
      query[i][3] = i;
      
    }
    Arrays.sort(query, (o1, o2) -> o1[1] - o2[1]);
    
    SegmentTreeRSQ st = new SegmentTreeRSQ(n + 1);
    
    int left = 0;
    for (int i = 0; i < q; i ++) {
      while (left < m && line[left][1] <= query[i][1]) {
        st.add(line[left][0], 1);
        left ++;
      }
      query[i][2] = (int)st.sum(query[i][0], n);
    }
    Arrays.sort(query, (o1, o2) -> o1[3] - o2[3]);
    for (int i = 0; i < q; i ++) {
      out.println(query[i][2]);
    }
  }

  public static void main(String[] args) {
    new Thread(null, new Runnable() {
      @Override
      public void run() {
        long start = System.currentTimeMillis();
        String debug = args.length > 0 ? args[0] : null;
        if (debug != null) {
          try {
            is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
          } catch (Exception e) {
            throw new RuntimeException(e);
          }
        }
        reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
        solve();
        out.flush();
        tr((System.currentTimeMillis() - start) + "ms");
      }
    }, "", 64000000).start();
  }

  private static java.io.InputStream is = System.in;
  private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
  private static java.util.StringTokenizer tokenizer = null;
  private static java.io.BufferedReader reader;

  public static String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }

  private static double nd() {
    return Double.parseDouble(next());
  }

  private static long nl() {
    return Long.parseLong(next());
  }

  private static int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }

  private static char[] ns() {
    return next().toCharArray();
  }

  private static long[] nal(int n) {
    long[] a = new long[n];
    for (int i = 0; i < n; i++)
      a[i] = nl();
    return a;
  }

  private static int[][] ntable(int n, int m) {
    int[][] table = new int[n][m];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[i][j] = ni();
      }
    }
    return table;
  }

  private static int[][] nlist(int n, int m) {
    int[][] table = new int[m][n];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[j][i] = ni();
      }
    }
    return table;
  }

  private static int ni() {
    return Integer.parseInt(next());
  }

  private static void tr(Object... o) {
    if (is != System.in)
      System.out.println(java.util.Arrays.deepToString(o));
  }
}