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# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("2 3 1");
            WillReturn.Add("1 1");
            WillReturn.Add("1 2");
            WillReturn.Add("2 2");
            WillReturn.Add("1 2");
            //3
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("10 3 2");
            WillReturn.Add("1 5");
            WillReturn.Add("2 8");
            WillReturn.Add("7 10");
            WillReturn.Add("1 7");
            WillReturn.Add("3 10");
            //1
            //1
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("10 10 10");
            WillReturn.Add("1 6");
            WillReturn.Add("2 9");
            WillReturn.Add("4 5");
            WillReturn.Add("4 7");
            WillReturn.Add("4 7");
            WillReturn.Add("5 8");
            WillReturn.Add("6 6");
            WillReturn.Add("6 7");
            WillReturn.Add("7 9");
            WillReturn.Add("10 10");
            WillReturn.Add("1 8");
            WillReturn.Add("1 9");
            WillReturn.Add("1 10");
            WillReturn.Add("2 8");
            WillReturn.Add("2 9");
            WillReturn.Add("2 10");
            WillReturn.Add("3 8");
            WillReturn.Add("3 9");
            WillReturn.Add("3 10");
            WillReturn.Add("1 10");
            //7
            //9
            //10
            //6
            //8
            //9
            //6
            //7
            //8
            //10
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();

        int[] wkArr = { };
        Action<string> SplitAct = pStr =>
            wkArr = pStr.Split(' ').Select(X => int.Parse(X)).ToArray();

        SplitAct(InputList[0]);

        int N = wkArr[0];
        int M = wkArr[1];

        int UB = N;
        int[,] RuisekiwaArr = new int[UB + 1, UB + 1];

        foreach (string EachStr in InputList.Skip(1).Take(M)) {
            SplitAct(EachStr);
            RuisekiwaArr[wkArr[0], wkArr[1]]++;
        }
        //PrintArr(RuisekiwaArr);

        // 横方向の累積和を求める
        for (int LoopR = 0; LoopR <= UB; LoopR++) {
            for (int LoopL = 0; LoopL <= UB; LoopL++) {
                if (LoopL > 0) {
                    RuisekiwaArr[LoopL, LoopR] += RuisekiwaArr[LoopL - 1, LoopR];
                }
            }
        }

        // 縦方向の累積和を求める
        for (int LoopL = 0; LoopL <= UB; LoopL++) {
            for (int LoopR = 0; LoopR <= UB; LoopR++) {
                if (LoopR > 0) {
                    RuisekiwaArr[LoopL, LoopR] += RuisekiwaArr[LoopL, LoopR - 1];
                }
            }
        }

        // クエリに回答する
        foreach (string EachStr in InputList.Skip(1 + M)) {
            SplitAct(EachStr);
            int QueryL = wkArr[0];
            int QueryR = wkArr[1];

            int Answer = RuisekiwaArr[QueryR, QueryR];
            Answer -= RuisekiwaArr[QueryL - 1, QueryR];
            Answer -= RuisekiwaArr[QueryR, QueryL - 1];
            Answer += RuisekiwaArr[QueryL - 1, QueryL - 1];
            Console.WriteLine(Answer);
        }
    }

    static void PrintArr(int[,] pArr)
    {
        for (int Y = 0; Y <= pArr.GetUpperBound(1); Y++) {
            for (int X = 0; X <= pArr.GetUpperBound(0); X++) {
                Console.Write("{0},", pArr[X, Y]);
            }
            Console.WriteLine();
        }
    }
}