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::collections::HashMap;
use std::collections::BTreeMap;
use std::cmp::Ordering;
use std::io::{ stdin, stdout, Write };


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

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

fn main() {
    let s: Vec<usize> = read_vec();
    let (n, m, q) = (s[0], s[1], s[2]);

    let mut data: Vec<Vec<i64>> = vec![vec![0; n]; n];

    for i in 0..m {
        let s: Vec<usize> = read_vec();
        data[s[0] - 1][s[1] - 1] += 1;
    }
    let mut sums: Vec<Vec<i64>> = vec![vec![0; n]; n];
    for i in 0..n {
        sums[i][0] = data[i][0];
        for j in 1..n {
            sums[i][j] = sums[i][j-1] + data[i][j];
        }
    }
    let mut s: Vec<String> = Vec::new();

    for i in 0..q {
        let mut qq = read_vec::<usize>();
        qq[0] -= 1;
        qq[1] -= 1;
        let mut ans = 0i64;
        for j in qq[0]..qq[1] + 1 {
            if qq[0] == 0 {
                ans += sums[j][qq[1]];
            } else {
                ans += sums[j][qq[1]] - sums[j][qq[0] - 1];
            }
        }
        s.push(ans.to_string());
    }
    println!("{}", s.connect("\n"));
}