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: Runtime Error)

import sys
input = sys.stdin.buffer.readline

n, m, q = map(int, input().split())

class TwoDimSum():
    def __init__(self, h, w):
        self.counts = [[0 for _ in range(w+1)] for _ in range(h+1)]
        self.s = [[0 for _ in range(w+1)] for _ in range(h+1)]

    def add_count(self, x, y):
        # 0-indexed
        self.counts[y+1][x+1] += 1

    def build(self):
        for i in range(h):
            for j in range(w):
                self.s[i+1][j+1] = self.s[i][j+1] + self.s[i+1][j] - self.s[i][j] + self.counts[i][j]

    def solve(self, x1, y1, x2, y2):
        return self.s[x2][y2] - self.s[x1][y2] - s[x2][y1] + s[x1][y1]

counts = TwoDimSum()
for _ in range(m):
    l, r = map(int, input().split())
    counts.add_count(l-1, r-1)
counts.build()

for i in range(q):
    x, y = map(int, input().split())
    ans.append(str(counts.solve(x, x, y, y)))
print("\n".join(ans))