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)

#![allow(unused)]
use io::*;
use std::collections::HashMap;

fn main() {
    let buf = read_string();
    let mut sc = Scanner::new(&buf);

    let (n, m, q): (usize, usize, usize) = (sc.next(), sc.next(), sc.next());

    let mut cnt: Vec<Vec<_>> = vec![vec![0usize; n + 1]; n + 1];
    for _ in 0..m {
        let (l, r): (usize, usize) = (sc.next(), sc.next());
        cnt[l][r] += 1;
    }

    cnt = (0..n + 1)
        .map(|i| {
            let mut sum = 0usize;
            cnt[i]
                .iter()
                .map(|c| {
                    sum += *c;
                    sum
                }).collect()
        }).collect();

    for _ in 0..q {
        let (l, r): (usize, usize) = (sc.next(), sc.next());
        let ans: usize = (l..r + 1).map(|i| cnt[i][r] - cnt[i][l - 1]).sum();
        println!("{}", &ans);
    }
}

pub mod io {
    use std;
    use std::io::Read;

    pub struct Scanner<'a> {
        iter: std::str::SplitWhitespace<'a>,
    }

    impl<'a> Scanner<'a> {
        pub fn new(buf: &'a String) -> Scanner<'a> {
            Scanner {
                iter: buf.split_whitespace(),
            }
        }

        pub fn next<T: std::str::FromStr>(&mut self) -> T {
            let s = self.iter.next().unwrap();
            s.parse().ok().expect("cannot parse string")
        }

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

    pub fn read_string() -> String {
        let mut buf = String::new();
        std::io::stdin().read_to_string(&mut buf).ok().unwrap();
        buf
    }

    fn read_line<T: std::str::FromStr>() -> T {
        let mut buf = String::new();
        std::io::stdin().read_line(&mut buf).unwrap();
        buf.trim().parse().ok().unwrap()
    }

    fn read_vec<T: std::str::FromStr>() -> Vec<T> {
        read_line::<String>()
            .split_whitespace()
            .map(|e| e.parse().ok().unwrap())
            .collect()
    }
}