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::str::FromStr;
use std::fmt::Debug;
use std::cmp;

#[allow(dead_code)]
fn read_as_vec<T>() -> Vec<T>
where T: FromStr, <T as FromStr>::Err : Debug{
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    s.trim().split_whitespace().map(|c| T::from_str(c).unwrap()).collect()

}

#[allow(dead_code)]
fn read_as_string() -> String{
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    s.trim().to_string()
}


fn print_vec(v: &Vec<Vec<usize>>){
    for row in v{
        println!("{:?}", row);
    }
}

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

    let mut table: Vec<Vec<usize>> = vec![vec![0;n];n];

    for _ in 0..m{
        let line: Vec<usize> = read_as_vec();
        table[line[0]-1][line[1]-1] += 1;
    }
    let mut cul_sum: Vec<Vec<usize>> = vec![vec![0;n];n];

    cul_sum[0][0] = table[0][0];
    for i in 1..n{
        cul_sum[i][0] = table[i][0] + cul_sum[i-1][0];
        cul_sum[0][i] = table[0][i] + cul_sum[0][i-1];
    }



    for i in 1..n{
        for j in 1..n{
            cul_sum[i][j] = cul_sum[i][j-1] + cul_sum[i-1][j] +
                table[i][j] - cul_sum[i-1][j-1];
        }
    }
    //print_vec(&cul_sum);
    for _ in 0..q{
        let line: Vec<usize> = read_as_vec();
        let (s, e) = (line[0]-1, line[1]-1);

        if s == 0{
            let ans = cul_sum[e][e];
            println!("{}", ans);
        }else{
            let ans = cul_sum[e][e] + cul_sum[s-1][s-1] - cul_sum[s-1][e] - cul_sum[e][s-1];
            println!("{}", ans);
        }
    }

}