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::FromStr;

#[allow(dead_code)]
fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

#[allow(dead_code)]
struct FenwickTree {
    seq: Vec<i64>,
}
#[allow(dead_code)]
impl FenwickTree {
    fn new(n: usize) -> FenwickTree {
        FenwickTree {
            seq: vec![0; n + 2],
        }
    }
    fn add(&mut self, index: i32, value: i64) {
        let mut index = (index + 3) as i32;
        while (index as usize) < self.seq.len() {
            self.seq[index as usize] += value;
            index += index & -index;
        }
    }
    // inclusive
    fn sum(&self, index: i32) -> i64 {
        let mut ret = 0;
        let mut index = (index + 3) as i32;
        while index > 0 {
            ret += self.seq[index as usize];
            index -= index & -index;
        }
        ret
    }
}

fn main() {
    let n = read::<usize>();
    let m = read::<usize>();
    let q = read::<usize>();
    let mut rls = vec![(0, 0); m];
    for i in 0..m {
        rls[i].1 = read::<usize>() - 1;
        rls[i].0 = read::<usize>() - 1;
    }
    rls.sort();
    let mut queries = vec![(0, 0, 0); q];
    for i in 0..q {
        queries[i].1 = read::<usize>() - 1;
        queries[i].0 = read::<usize>() - 1;
        queries[i].2 = i;
    }
    queries.sort();
    let mut anss = vec![0; q];
    let mut ftree = FenwickTree::new(n + 10);
    let mut rls_index = 0;
    for i in 0..q {
        let r = queries[i].0;
        while rls_index < rls.len() && rls[rls_index].0 <= r {
            ftree.add(rls[rls_index].1 as i32, 1);
            rls_index += 1;
        }
        let l = queries[i].1;
        let index = queries[i].2;
        anss[index] = rls_index - ftree.sum(l as i32 - 1) as usize;
    }
    for i in 0..q {
        println!("{}", anss[i]);
    }
}