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 JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

"use strict";

function _toConsumableArray(arr) { return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _nonIterableSpread(); }

function _nonIterableSpread() { throw new TypeError("Invalid attempt to spread non-iterable instance"); }

function _arrayWithoutHoles(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } }

function _toArray(arr) { return _arrayWithHoles(arr) || _iterableToArray(arr) || _nonIterableRest(); }

function _iterableToArray(iter) { if (Symbol.iterator in Object(iter) || Object.prototype.toString.call(iter) === "[object Arguments]") return Array.from(iter); }

function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _nonIterableRest(); }

function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance"); }

function _iterableToArrayLimit(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }

function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }

function _main() {
  // ----------
  (function (input) {
    var lines = input.split("\n");

    var _splitNum = splitNum(lines[0]),
        _splitNum2 = _slicedToArray(_splitNum, 3),
        N = _splitNum2[0],
        M = _splitNum2[1],
        Q = _splitNum2[2];

    var trains = lines.slice(1, M + 1).map(function (line) {
      var _splitNum3 = splitNum(line),
          _splitNum4 = _slicedToArray(_splitNum3, 2),
          l = _splitNum4[0],
          r = _splitNum4[1];

      return {
        l,
        r
      };
    });
    var queries = lines.slice(M + 1).map(function (line) {
      var _splitNum5 = splitNum(line),
          _splitNum6 = _slicedToArray(_splitNum5, 2),
          p = _splitNum6[0],
          q = _splitNum6[1];

      return {
        p,
        q
      };
    }).slice(0, Q);
    var count = makeArr([N + 1, N + 1], 0);
    var _iteratorNormalCompletion = true;
    var _didIteratorError = false;
    var _iteratorError = undefined;

    try {
      for (var _iterator = trains[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
        var _step$value = _step.value,
            l = _step$value.l,
            r = _step$value.r;
        count[r][l]++;
      }
    } catch (err) {
      _didIteratorError = true;
      _iteratorError = err;
    } finally {
      try {
        if (!_iteratorNormalCompletion && _iterator.return != null) {
          _iterator.return();
        }
      } finally {
        if (_didIteratorError) {
          throw _iteratorError;
        }
      }
    }

    var sum = makeArr([N + 1, N + 1], 0);
    var _iteratorNormalCompletion2 = true;
    var _didIteratorError2 = false;
    var _iteratorError2 = undefined;

    try {
      for (var _iterator2 = range(1, N + 1)[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
        var r = _step2.value;
        var _iteratorNormalCompletion4 = true;
        var _didIteratorError4 = false;
        var _iteratorError4 = undefined;

        try {
          for (var _iterator4 = range(1, N + 1)[Symbol.iterator](), _step4; !(_iteratorNormalCompletion4 = (_step4 = _iterator4.next()).done); _iteratorNormalCompletion4 = true) {
            var l = _step4.value;
            sum[r][l] = sum[r][l - 1] + count[r][l];
          }
        } catch (err) {
          _didIteratorError4 = true;
          _iteratorError4 = err;
        } finally {
          try {
            if (!_iteratorNormalCompletion4 && _iterator4.return != null) {
              _iterator4.return();
            }
          } finally {
            if (_didIteratorError4) {
              throw _iteratorError4;
            }
          }
        }
      }
    } catch (err) {
      _didIteratorError2 = true;
      _iteratorError2 = err;
    } finally {
      try {
        if (!_iteratorNormalCompletion2 && _iterator2.return != null) {
          _iterator2.return();
        }
      } finally {
        if (_didIteratorError2) {
          throw _iteratorError2;
        }
      }
    }

    var _iteratorNormalCompletion3 = true;
    var _didIteratorError3 = false;
    var _iteratorError3 = undefined;

    try {
      for (var _iterator3 = queries[Symbol.iterator](), _step3; !(_iteratorNormalCompletion3 = (_step3 = _iterator3.next()).done); _iteratorNormalCompletion3 = true) {
        var _step3$value = _step3.value,
            p = _step3$value.p,
            q = _step3$value.q;
        var result = 0;
        var _iteratorNormalCompletion5 = true;
        var _didIteratorError5 = false;
        var _iteratorError5 = undefined;

        try {
          for (var _iterator5 = range(p, q + 1)[Symbol.iterator](), _step5; !(_iteratorNormalCompletion5 = (_step5 = _iterator5.next()).done); _iteratorNormalCompletion5 = true) {
            var _r = _step5.value;
            result += sum[_r][q] - sum[_r][p - 1];
          }
        } catch (err) {
          _didIteratorError5 = true;
          _iteratorError5 = err;
        } finally {
          try {
            if (!_iteratorNormalCompletion5 && _iterator5.return != null) {
              _iterator5.return();
            }
          } finally {
            if (_didIteratorError5) {
              throw _iteratorError5;
            }
          }
        }

        console.log(result);
      }
    } catch (err) {
      _didIteratorError3 = true;
      _iteratorError3 = err;
    } finally {
      try {
        if (!_iteratorNormalCompletion3 && _iterator3.return != null) {
          _iterator3.return();
        }
      } finally {
        if (_didIteratorError3) {
          throw _iteratorError3;
        }
      }
    }
  })(require("fs").readFileSync("/dev/stdin", "utf8"));

  function splitNum(line) {
    return (Array.isArray(line) ? line : line.split(/\s+/)).map(function (n) {
      return parseInt(n);
    });
  }
  /**
   * Iterates over integers in [start, end).
   */


  function* range(start, end) {
    for (var i = start; i < end; i++) {
      yield i;
    }
  }
  /**
   * Iterates over integers in [end, start) in desc order.
   */


  /**
   * Make k-dimentional array.
   */
  function makeArr(size, defaultValue) {
    if (!Array.isArray(size)) {
      size = [size];
    }

    if (size.length === 1) {
      return new Array(size[0]).fill(defaultValue);
    }

    var _size = size,
        _size2 = _toArray(_size),
        here = _size2[0],
        rest = _size2.slice(1);

    return new Array(here).fill(null).map(function () {
      return makeArr(rest, defaultValue);
    });
  }
  /**
   * Sort given array with keys.
   * sortByKey(arr, ['key1', 'key2'])
   * sortByKey(arr, [['key1', -1], 'key2'])
   */
  // ----------

}

_main();