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: Accepted)

using System;
using System.Collections;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections.Generic;
namespace Collections
{
	class program
	{
    //static long MAX_LONG = 5000000000000000;
		static void Main(string[] args)
		{

			// 入力
      int[] input = Console.ReadLine().Split().Select(p => int.Parse(p)).ToArray();
      int N = input[0];
      int M = input[1];
      int Q = input[2];

      // 都市iを出発してjの距離を走る電車の数をtrain[i][j]に記録する
      int[,] train = new int[N+1, N+1];
      for(int i=0; i<M; i++)
      {
          input = Console.ReadLine().Split().Select(p => int.Parse(p)).ToArray();
          int L = input[0];
          int R = input[1];
          train[L, R-L] += 1;
      }

      // 都市iを出発して、jの距離以下を走る電車の数をあらかじめ求めておく(部分和)
      int[,] partsum = new int[N+1, N+1];
      for(int i=1; i<=N; i++)
      {
        for(int j=0; j<=N; j++)
        {
          if(j==0)
          {
            partsum[i,j] = train[i,j];
          }
          else
          {
            partsum[i,j] = partsum[i, j-1] + train[i,j];
          }
        }
      }

      //質問に答える
      // pから出発してqまでに到着する電車の数は
      // 都市pを出発してq-p以下の距離を走る電車の数＋都市p+1を出発して・・・
      for(int q =0; q<Q; q++)
      {
        input = Console.ReadLine().Split().Select(p => int.Parse(p)).ToArray();
        int L = input[0];
        int R = input[1];

        int ans = 0;
        for(int i=L; i<=R; i++)
        {
          ans += partsum[i,R-i];
        }
        Console.WriteLine(ans + "");
      }
    }
	}
}