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.Generic;
using System.Linq;
using System.Text;

namespace Contest
{
    class Scanner
    {
        private string[] line = new string[0];
        private int index = 0;
        public string Next()
        {
            if (line.Length <= index)
            {
                line = Console.ReadLine().Split(' ');
                index = 0;
            }
            var res = line[index];
            index++;
            return res;
        }
        public int NextInt()
        {
            return int.Parse(Next());
        }
        public long NextLong()
        {
            return long.Parse(Next());
        }
        public string[] Array()
        {
            line = Console.ReadLine().Split(' ');
            index = line.Length;
            return line;
        }
        public int[] IntArray()
        {
            var array = Array();
            var result = new int[array.Length];
            for (int i = 0; i < array.Length; i++)
            {
                result[i] = int.Parse(array[i]);
            }

            return result;
        }
        public long[] LongArray()
        {
            var array = Array();
            var result = new long[array.Length];
            for (int i = 0; i < array.Length; i++)
            {
                result[i] = long.Parse(array[i]);
            }

            return result;
        }
    }

    struct S
    {
        public int X, Y;
    }

    class Program
    {
        private int N, M, Q;
        private int[] p, q;

        private long[,] Sum;

        private void Scan()
        {
            var sc = new Scanner();
            N = sc.NextInt();
            M = sc.NextInt();
            Q = sc.NextInt();
            Sum = new long[N + 1, N + 1];
            p = new int[Q];
            q = new int[Q];
            for (int i = 0; i < M; i++)
            {
                int l = sc.NextInt();
                int r = sc.NextInt();
                Sum[l, r]++;
            }

            for (int i = 0; i < Q; i++)
            {
                p[i] = sc.NextInt();
                q[i] = sc.NextInt();
            }
        }

        public void Solve()
        {
            Scan();
            for (int i = 1; i <= N; i++)
            {
                long line = 0;
                for (int j = 1; j <= N; j++)
                {
                    line += Sum[i, j];
                    Sum[i, j] = Sum[i - 1, j] + line;
                }
            }
            var sb = new StringBuilder();
            for (int i = 0; i < Q; i++)
            {
                int pp = p[i];
                int qq = q[i];
                long a = Sum[qq, qq];
                long b = Sum[pp - 1, qq];
                long c = Sum[qq, pp - 1];
                long d = Sum[pp - 1, pp - 1];
                sb.AppendLine((a - b - c + d).ToString());

            }
            Console.Write(sb.ToString());
        }

        static void Main() => new Program().Solve();
    }
}