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)

fn main() {
    proconio::input! {
        n: usize,
        m: usize,
        q: usize,
        mut lr: [(usize,usize);m],
        pq: [(usize,usize);q],
    }
    lr.sort_unstable();
    let mut k: Vec<usize>=(0..q).collect();
    k.sort_unstable_by_key(|k|pq[*k]);
    let mut b=vec![0;n+1];
    for &(_,r) in &lr {
        let mut i=r;
        while i<=n {
            b[i]+=1;
            i+=i&i.wrapping_neg();
        }
    }
    let mut r=vec![0;q];
    let mut u=0;
    let mut v=0;
    for i in 1..=n {
        while u<m && lr[u].0<i {
            let mut i=lr[u].1;
            while i<=n {
                b[i]-=1;
                i+=i&i.wrapping_neg();
            }
            u+=1;
        }
        while v<q && pq[k[v]].0==i {
            let mut i=pq[k[v]].1;
            let mut s=0;
            while i>0 {
                s+=b[i];
                i-=i&i.wrapping_neg();
            }
            r[k[v]]=s;
            v+=1;
        }
    }
    for r in r {
        println!("{}",r);
    }
}