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"
)

type Range struct {
	L, R int
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	var N, M, Q int
	scanner.Scan()
	fmt.Sscanf(scanner.Text(), "%d %d %d", &N, &M, &Q)

	dp := make(map[Range]int)
	for i := 0; i < M; i++ {
		var L, R int
		scanner.Scan()
		fmt.Sscanf(scanner.Text(), "%d %d", &L, &R)
		dp[Range{L, R}]++
	}

	for i := 1; i <= N; i++ {
		t := Range{1, i}
		for t.R <= N {
			dp[t] = dp[t] +
				dp[Range{t.L, t.R - 1}] +
				dp[Range{t.L + 1, t.R}] -
				dp[Range{t.L + 1, t.R - 1}]
			t.L++
			t.R++
		}
	}

	for Q > 0 {
		Q--
		var p, q int
		scanner.Scan()
		fmt.Sscanf(scanner.Text(), "%d %d", &p, &q)
		fmt.Println(dp[Range{p, q}])
	}

}