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)

#[test]
fn test_solve() {
    assert_eq!(solve("2 3 1\n1 1\n1 2\n2 2\n1 2\n"), "3\n");
    assert_eq!(solve("10 3 2\n1 5\n2 8\n7 10\n1 7\n3 10\n"), "1\n1\n");
    assert_eq!(solve("10 10 10\n1 6\n2 9\n4 5\n4 7\n4 7\n5 8\n6 6\n6 7\n7 9\n10 10\n1 8\n1 9\n1 10\n2 8\n2 9\n2 10\n3 8\n3 9\n3 10\n1 10\n"), "7\n9\n10\n6\n8\n9\n6\n7\n8\n10\n");
}

fn solve(src: &str) -> String {
    let mut sc = Scanner::from_str(src);

    let n: usize = sc.read();
    let m: usize = sc.read();
    let q: usize = sc.read();
    let lr: Vec<(usize, usize)> = (0..m).map(|_| (sc.read(), sc.read())).collect();
    let ab: Vec<(usize, usize)> = (0..q).map(|_| (sc.read(), sc.read())).collect();
    
    let mut cnt = vec![vec![0; n]; n];
    for &(l, r) in &lr {
        cnt[l-1][r-1] += 1;
    }
    let mut sum = vec![vec![0; n+1]; n+1];
    for l in 0..n {
        for r in 0..n {
            sum[l+1][r+1] = cnt[l][r] + sum[l+1][r] + sum[l][r+1] - sum[l][r];
        }
    }

    let mut ret = String::new();
    use std::fmt::Write;

    for &(a, b) in &ab {
        let num = sum[b][b] + sum[a-1][a-1] - sum[a-1][b] - sum[b][a-1];
        writeln!(&mut ret, "{}", num).unwrap();
    }

    ret
}
fn main() {
    let mut buf = String::new();
    use std::io::{Read, Write};
    std::io::stdin().read_to_string(&mut buf).unwrap();
    std::io::stdout().write_all(solve(&buf).as_bytes()).unwrap();
}
struct Scanner<'a>(std::str::SplitWhitespace<'a>);
impl<'a> Scanner<'a> {
    fn from_str(src: &str) -> Scanner {
        Scanner(src.split_whitespace())
    }
    fn get(&mut self) -> &str {
        self.0.next().unwrap()
    }
    fn read<T: std::str::FromStr>(&mut self) -> T {
        self.get().parse().ok().unwrap()
    }
}