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: Time Limit Exceeded)

package main

import (
	"fmt"
	"os"
	"sort"
)

func debug(f string, a ...interface{}) {
	fmt.Fprintf(os.Stderr, f, a...)
	fmt.Fprintln(os.Stderr, "")
}

// pq  +----+
// lr  +-----------+
func main() {
	var N, M, Q int

	fmt.Scanf("%d %d %d\n", &N, &M, &Q)
	lrs := make(map[int][]int)
	var ls = make([]int, 0)
	var l, r int
	for i := 0; i < M; i++ {
		fmt.Scanf("%d %d\n", &l, &r)
		if lr, ok := lrs[l]; ok {
			lrs[l] = append(lr, r)
		} else {
			ls = append(ls, l)
			lrs[l] = []int{r}
		}
		fmt.Fprintf(os.Stderr, "%d, %d   : %v\n", l, r, lrs)
	}
	sort.Ints(ls)
	fmt.Fprintf(os.Stderr, "%v\n", ls)

	for i := 0; i < Q; i++ {
		var p, q int
		fmt.Scanf("%d %d\n", &p, &q)
		//fmt.Fprintf(os.Stderr, "[%d] p=%d, q=%d\n", i+1, p, q)
		count := 0
		//fmt.Fprintf(os.Stderr, "p=%d, q=%d\n", p, q)
		for _, l := range ls {
			//fmt.Fprintf(os.Stderr, "pre p=%d, q=%d l=%d, %v\n", p, q, l, lrs[l])
			if p <= l {
				for _, r := range lrs[l] {
					if r <= q {
						count += 1
						//fmt.Fprintf(os.Stderr, "  OK [%d] p=%d, q=%d  l=%d\n", i+1, p, q, l)
					} else {
						//fmt.Fprintf(os.Stderr, "  NG [%d] p=%d, q=%d  l=%d\n", i+1, p, q, l)
					}
				}
			} else {
				//fmt.Fprintf(os.Stderr, "  NG [%d] p=%d, q=%d  l=%d\n", i+1, p, q, l)
			}
		}
		//fmt.Fprintf(os.Stderr, "p=%d, q=%d  -> %d\n", p, q, count)
		fmt.Println(count)
	}
}