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::cmp::{self, Ordering};
use std::collections::*;
use std::io::{self, Read};

const MOD: usize = 1000000007;

fn main() {
    let stdin = io::stdin();
    let mut sc = Scanner::new(stdin.lock());

    let n: usize = sc.read().unwrap();
    let m: usize = sc.read().unwrap();
    let q: usize = sc.read().unwrap();

    let mut t1 = Vec::with_capacity(n);
    for _ in 0..n {
        t1.push(vec![0 as i32; n]);
    }
    for _ in 0..m {
        let li: usize = sc.read().unwrap();
        let ri: usize = sc.read().unwrap();
        t1[li - 1][ri - 1] = t1[li - 1][ri - 1] + 1;
    }

    let mut t2 = Vec::with_capacity(n);
    for _ in 0..n {
        t2.push(vec![0 as i32; n]);
    }
    for i in 0..n {
        for j in 0..n {
            t2[i][j] = match (i > 0, j > 0) {
                (false, false) => t1[i][j],
                (false, true) => t1[i][j] + t2[i][j - 1],
                (true, false) => t1[i][j] + t2[i - 1][j],
                (true, true) => t1[i][j] + t2[i - 1][j] + t2[i][j - 1] - t2[i - 1][j - 1],
            };
        }
    }

    // for l in &t1 {
    //     println!("{:?}", l);
    // }
    // println!("----------");
    // for l in &t2 {
    //     println!("{:?}", l);
    // }

    for i in 0..q {
        let pi: usize = sc.read().unwrap();
        let pi = pi - 1;
        let qi: usize = sc.read().unwrap();
        let qi = qi - 1;

        if pi == 0 {
            println!("{}", t2[qi][qi]);
        } else {
            println!(
                "{}",
                t2[qi][qi] - t2[qi][pi - 1] - t2[pi - 1][qi] + t2[pi - 1][pi - 1]
            );
        }
    }
}

struct Scanner<R: Read> {
    reader: R,
}

impl<R: Read> Scanner<R> {
    fn new(reader: R) -> Scanner<R> {
        Scanner { reader: reader }
    }

    fn read<T: std::str::FromStr>(&mut self) -> Option<T> {
        self.reader
            .by_ref()
            .bytes()
            .map(|b| b.unwrap() as char)
            .skip_while(|c| c.is_whitespace())
            .take_while(|c| !c.is_whitespace())
            .collect::<String>()
            .parse()
            .ok()
    }

    fn read_vec<T: std::str::FromStr>(&mut self, n: usize) -> Option<Vec<T>> {
        (0..n).map(|_| self.read()).collect()
    }

    fn read_vec2d<T: std::str::FromStr>(&mut self, m: usize, n: usize) -> Option<Vec<Vec<T>>> {
        (0..m).map(|_| self.read_vec(n)).collect()
    }

    fn read_board(&mut self, n: usize) -> Option<Vec<Vec<char>>> {
        (0..n)
            .map(|_| {
                self.read::<String>()
                    .map(|s| s.chars().collect::<Vec<char>>())
            })
            .collect()
    }
}