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 (1.42.0) (judge verdict: Accepted)

use std::io::{stdin, Read};
use std::str::FromStr;


fn read<T: FromStr>() -> T {
    let stdin = stdin();
    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")
}

fn main() {
    let N: usize = read();
    let M: usize = read();
    let Q: usize = read();
    let mut L: Vec<usize> = vec![];
    let mut R: Vec<usize> = vec![];
    let mut p: Vec<usize> = vec![];
    let mut q: Vec<usize> = vec![];
    for _ in 0..M {
        L.push(read::<usize>() - 1);
        R.push(read::<usize>() - 1);
    }
    for _ in 0..Q {
        p.push(read::<usize>() - 1);
        q.push(read::<usize>() - 1);
    }

    let mut train = vec![vec![0; N + 1]; N + 1];
    for i in 0..M {
        train[L[i] + 1][R[i] + 1] += 1;
    }
    let mut cum = vec![vec![0; N + 1]; N + 1];
    for i in 0..N {
        for j in 0..N {
            cum[i + 1][j + 1] = cum[i][j + 1] + cum[i + 1][j] + train[i + 1][j + 1] - cum[i][j];
        }
    }

    for i in 0..Q {
        let ret = cum[q[i] + 1][q[i] + 1] - cum[q[i] + 1][p[i]] - cum[p[i]][q[i] + 1] + cum[p[i]][p[i]];
        println!("{}", ret);
    }
}