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# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;
using System.Text;

public class Program
{

    public void Proc()
    {
        int[] inpt = Reader.ReadLine().Split(' ').Select(a => int.Parse(a)).ToArray();

        this.CityCount = inpt[0];
        this.TrainCount = inpt[1];
        this.QueryCount = inpt[2];
        this.EndCount = new int[this.CityCount + 1];
        this.StartCount = new int[this.CityCount + 1];
        int[] flags = new int[this.CityCount + 1];
        Dictionary<int, int> endList = new Dictionary<int, int>();
        Dictionary<int, int> startList = new Dictionary<int, int>();
        for (int i = 0; i < this.TrainCount; i++) {
            inpt = Reader.ReadLine().Split(' ').Select(a => int.Parse(a)-1).ToArray();
            if(!endList.ContainsKey(inpt[1])) {
                endList.Add(inpt[1], 0);
            }
            endList[inpt[1]]++;
            if(!startList.ContainsKey(inpt[0])) {
                startList.Add(inpt[0], 0);
            }
            startList[inpt[0]]++;
            if(inpt[1] - inpt[0] <= 1) {
                continue;
            }
            flags[inpt[0]]++;
            flags[inpt[1] - 1]--;
        }
        this.Matagi = new int[this.CityCount];

        if(endList.ContainsKey(0)) {
            EndCount[0] = endList[0];
        }
        if(startList.ContainsKey(0)) {
            StartCount[0] = startList[0];
        }
        this.Matagi[0] = flags[0];
        for (int i = 1; i < this.CityCount; i++) {
            EndCount[i] = EndCount[i - 1];
            if(endList.ContainsKey(i)) {
                EndCount[i] += endList[i];
            }
            StartCount[i] = StartCount[i - 1];
            if(startList.ContainsKey(i)) {
                StartCount[i] += startList[i];
            }
            this.Matagi[i] = this.Matagi[i - 1] + flags[i];
        }

        StringBuilder ans = new StringBuilder();
        for (int i = 0; i < QueryCount; i++) {
            inpt = Reader.ReadLine().Split(' ').Select(a => int.Parse(a) - 1).ToArray();
            ans.AppendLine(GetQueryAns(inpt[0], inpt[1]).ToString());
        }
        Console.Write(ans.ToString());

    }


    private int GetQueryAns(int frm, int to) {
        int cnt = EndCount[to];
        cnt += StartCount[to];
        cnt -= Matagi[to];
        if(frm>0) {
            cnt -= EndCount[frm - 1];
            cnt -= StartCount[frm - 1];
            cnt -= Matagi[frm - 1];
        }
        return cnt;
    }
    private int[] Matagi;
    private int[] EndCount;
    private int[] StartCount;

    private int CityCount;
    private int TrainCount;
    private int QueryCount;


    public class Reader
    {
        static StringReader sr;
        public static bool IsDebug = false;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (sr == null)
                {
                    sr = new StringReader(InputText.Trim());
                }
                return sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        private static string InputText = @"

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


";
    }

    public static void Main(string[] args)
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}