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 Rust (1.15.1) (judge verdict: Accepted)

use std::io::*;
use std::str::*;

fn scan_token<T: FromStr>() -> T {
    stdin().bytes()
        .map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>()
        .parse::<T>().ok().unwrap()
}

fn scan_line<T: FromStr>() -> Vec<T> {
    let mut buf = String::new();
    stdin().read_line(&mut buf).unwrap();
    buf.split_whitespace().map( |token| token.parse::<T>().ok().unwrap() ).collect()
}

fn add(acc: &mut Vec<Vec<i32>>, frx: usize, fry: usize, tox: usize, toy: usize, v: i32) {
    acc[frx][fry] += v;
    acc[frx][toy] -= v;
    acc[tox][fry] -= v;
    acc[tox][toy] += v;
}

fn main() {
    let max_n = 505;
    let n: i32 = scan_token();
    let m: i32 = scan_token();
    let q: i32 = scan_token();

    let mut acc: Vec<Vec<i32>> = vec![vec![0; max_n]; max_n];

    for i in 0..m {
        let l: usize = scan_token();
        let r: usize = scan_token();
        add(&mut acc, 0, r, l + 1, max_n - 1, 1)
    }

    for i in 0..max_n {
        for j in 0..(max_n - 1) {
            acc[i][j + 1] += acc[i][j];
        }
    }

    for j in 0..max_n {
        for i in 0..(max_n - 1) {
            acc[i + 1][j] += acc[i][j];
        }
    }

    for i in 0..q {
        let p: usize = scan_token();
        let q: usize = scan_token();
        println!("{}", acc[p][q]);
    }
}