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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc *bufio.Scanner

func init() {
	sc = bufio.NewScanner(os.Stdin)
	buffsize := 1000000
	buff := make([]byte, buffsize)
	sc.Buffer(buff, buffsize)
	sc.Split(bufio.ScanWords)
}

func loadint() (result int) {
	sc.Scan()
	result, _ = strconv.Atoi(sc.Text())
	return
}

func loadstr() string {
	sc.Scan()
	return sc.Text()
}

func loadints(n int) []int {
	xs := make([]int, n)
	for i := 0; i < n; i++ {
		xs[i] = loadint()
	}
	return xs
}

func main() {
	n := loadint()
	m := loadint()
	q := loadint()
	ls := make([]int, m)
	rs := make([]int, m)
	ps := make([]int, q)
	qs := make([]int, q)
	for i := 0; i < m; i++ {
		ls[i] = loadint()
		rs[i] = loadint()
	}
	for i := 0; i < q; i++ {
		ps[i] = loadint()
		qs[i] = loadint()
	}
	t := make([][]int, n+1)
	for i := 0; i <= n; i++ {
		t[i] = make([]int, n+1)
	}
	for i := 0; i < m; i++ {
		t[ls[i]][rs[i]]++
	}
	for i := 0; i <= n; i++ {
		r := 0
		for j := 0; j <= n; j++ {
			r += t[i][j]
			t[i][j] = r
		}
	}
	for i := 0; i <= n; i++ {
		r := 0
		for j := 0; j <= n; j++ {
			r += t[j][i]
			t[j][i] = r
		}
	}
	for i := 0; i < q; i++ {
		x := qs[i]
		y := ps[i] - 1
		result := t[x][x] - t[x][y] - t[y][x] + t[y][y]
		fmt.Println(result)
	}
}