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 PyPy3 (2.4.0) (judge verdict: Accepted)


def main():
    N,M,Q = map(int, input().split())

    X = [[0 for _ in range(N)] for _ in range(N)]
    for i in range(M):
        l,r = map(int, input().split())
        X[l-1][r-1] += 1

    query = [tuple(map(int, input().split())) for _ in range(Q)]

    """
    C[i][j]：iから出発してjまで（ｊを含む）のどこかに行くもの
    C[i][j] = X[i][i] + X[i][i+1] + ... + X[i][j-1] + X[i][j]
    """
    C =  [[0 for _ in range(N)] for _ in range(N)]
    for i in range(N):
        for j in range(N):
            C[i][j] = C[i][j-1] + X[i][j]


    """
    print("---------------")
    for a in C:
        print(a)
    """

    for p,q in query:
        cnt = 0
        for r in range(p-1,q):
            cnt += C[r][q-1]
        print(cnt)


if __name__ == "__main__":
    main()