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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

// https://beta.atcoder.jp/contests/abc106

#define SUBMIT
//#define DEBUG

#include <iostream>
#include <sstream>
#include <vector>
#include <algorithm>
#include <numeric>
#include <cstring>
#include <cmath>
#include <unordered_map>
#include <map>

using namespace std;
using ui64 = unsigned long long;
using i64 = long long;

const int MAX_N = 500;
const int MAX_M = 200000;
int L[MAX_M + 1];
int R[MAX_M + 1];
// ans[i][j] 区間[i, j]に完全に含まれる電車の数
int memo[MAX_N + 1][MAX_N + 1];
//int ans[MAX_N + 1][MAX_N + 1];
int dp[MAX_N + 1][MAX_N + 1];

int main() {
#ifdef SUBMIT
    auto& stream = cin;
#else
    auto s = std::string(R"(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
)");
    stringstream stream(s);
#endif
    int N, M, Q;
    stream >> N >> M >> Q;

    memset(memo, 0, sizeof(memo));
//    memset(ans, 0, sizeof(ans));
    memset(dp, 0, sizeof(dp));

    for (int i = 0; i < M; ++i) {
        stream >> L[i] >> R[i];
        memo[L[i]][R[i]]++;
//        for (int l = L[i]; l >= 0; --l) {
//            for (int r = R[i]; r <= N; ++r) {
//                ans[l][r]++;
//            }
//        }
    }

    for (int i = N; i >= 0; --i) {
        for (int j = 1; j <= N; ++j) {
            dp[i][j] = memo[i][j];
            if (j != 1) dp[i][j] += dp[i][j - 1];
        }
    }

    for (int i = N; i >= 0; --i) {
        for (int j = 1; j <= N; ++j) {
            if (i != N) dp[i][j] += dp[i + 1][j];
        }
    }


    int p, q;
    for (int i = 0; i < Q; ++i) {
        stream >> p >> q;
        cout << dp[p][q] << endl;
    }

#ifdef DEBUG
    cout << "memo" << endl;
    for (int i = 1; i <= N; ++i) {
        for (int j = 1; j <= N; ++j) {
            cout << memo[i][j] << " ";
        }
        cout << endl;
    }

    cout << "dp" << endl;
    for (int i = 1; i <= N; ++i) {
        for (int j = 1; j <= N; ++j) {
            cout << dp[i][j] << " ";
        }
        cout << endl;
    }

    cout << "ans" << endl;
    for (int i = 1; i <= N; ++i) {
        for (int j = 1; j <= N; ++j) {
            cout << ans[i][j] << " ";
        }
        cout << endl;
    }
#endif

    return 0;
}