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 Scala (2.11.7) (judge verdict: Accepted)

import scala.io.StdIn._
object Main extends App {
  val sr = new StdinReader
  val n, m, q = sr.nextInt

  val arr = Array.ofDim[Int](n + 1, n + 1)
  (1 to m).foreach{i =>
    val l, r = sr.nextInt
    arr(l)(r) += 1
  }

  for {
    l <- (1 to n)
    r <- (1 to n)
  } {
    arr(l)(r) += arr(l - 1)(r) + arr(l)(r - 1) - arr(l - 1)(r - 1)
  }

  val ans = Array.ofDim[Int](n + 1, n + 1)
  for {
    l <- (1 to n)
    r <- (1 to n)
  } {
    ans(l)(r) = arr(r)(r) - arr(l - 1)(r) - arr(r)(l - 1) + arr(l - 1)(l - 1)
  }

  (1 to q).foreach{i =>
    val l, r = sr.nextInt
    println(ans(l)(r))
  }
}




class StdinReader {
  val is = System.in
  val buffer = new Array[Byte](1024 * 1024)
  var size = 0
  var pos = 0

  private def readByte: Byte = {
    if (pos >= size) {
      pos = 0;
      size = is.read(buffer);
    }
    if (size < 0) -1
    else {
      val ret = buffer(pos)
      pos += 1
      ret
    }
  }

  // support single byte char only
  def next: String = {
    @scala.annotation.tailrec
    def r(sb: StringBuilder, reading: Boolean): String = {
      readByte match {
        case b if ('!' <= b && b <= '~') => r(sb.append(b.asInstanceOf[Char]), true)
        case _ => if (reading) sb.toString else r(sb, false)
      }
    }
    r(new StringBuilder, false)
  }

  def nextInt: Int = {
    @scala.annotation.tailrec
    def r(i: Int, reading: Boolean): Int = {
      readByte match {
        case '-' => r(i * -1, true)
        case b if '0' <= b && b <= '9' => r(i * 10 + (b - '0'), true)
        case _ => if (reading) i else r(i, false)
      }
    }
    r(0, false)
  }
}