#include <iostream>
#include <complex>
#include <utility>
#include <vector>
#include <algorithm>
#include <list>
#include <cstdio>

using namespace std;

typedef complex<double> POINT;
typedef pair<POINT, POINT> LINE;

const double EPSIRON = 0.000000001;

bool OnArea(int leftx, const LINE& l)
{
  double x = (double)leftx + 0.5;
  if (l.first.real() < x && x < l.second.real() ||
      l.second.real() < x && x < l.first.real()){
    return true;
  }
  return false;
}

double CalcCrossPoint(const LINE& l, double x)
{
  double x1 = l.first.real();
  double y1 = l.first.imag();
  double x2 = l.second.real();
  double y2 = l.second.imag();

  double a = (y2 - y1) / (x2 - x1);
  double b = y1 - a * x1;
  
  //cout << a * x + b << " " << endl;

  return a * x + b;
}

pair<double, double> CalcCrossPointPair(const LINE& l, int leftx)
{
  double y1 = CalcCrossPoint(l, (double)leftx);
  double y2 = CalcCrossPoint(l, (double)(leftx + 1));
  if (y1 > y2){
    swap(y1, y2);
  }

  //printf("(%.01lf,%.01lf)", y1, y2);

  return make_pair(y1, y2);
}

bool IsTate(const LINE& l)
{
  return abs(l.first.real() - l.second.real()) < EPSIRON;
}

int GetSign(double f)
{
  if (abs(f) < EPSIRON){
    return 1;
  }
  if (f / abs(f) > 0.0){
    return 1;
  } else {
    return -1;
  }
}

int CountArea(const vector<LINE>& lines, int leftx)
{
  vector<pair<double, double> > p;
  for (vector<LINE>::const_iterator it = lines.begin();
       it != lines.end(); ++it){
    const LINE& line = *it;
    if (OnArea(leftx, line)){
      p.push_back(CalcCrossPointPair(line, leftx));
    }
  }

  sort(p.begin(), p.end());

  if (p.empty()){
    return 0;
  }
  //cout << endl;

  list<pair<int, int> > range;

  for (int i = 0; i < (int)p.size(); i += 2){
    double ylow = p[i].first;
    double yhigh = p[i + 1].second;
    int begin, end;

    if (fmod(abs(ylow), 1.0) < EPSIRON ||
	1.0 - fmod(abs(ylow), 1.0) < EPSIRON){
      begin = GetSign(ylow) * (int)(abs(ylow) + 0.5);
    } else {
      begin = (int)ylow;
      if (ylow < 0.0){
	--begin;
      }
    }

    if (fmod(abs(yhigh), 1.0) < EPSIRON ||
	1.0 - fmod(abs(yhigh), 1.0) < EPSIRON){
      end = GetSign(yhigh) * (int)(abs(yhigh) + 0.5);
    } else {
      end = (int)yhigh + 1;
      if (yhigh < 0.0){
	--end;
      }
    }

    range.push_back(make_pair(begin, end));
  }

  list<pair<int, int> >::iterator it1 = range.begin();
  while (it1 != range.end()){
    list<pair<int, int> >::iterator it2 = it1;
    ++it2;
    if (it2 == range.end()){
      break;
    }

    if (it1->second > it2->first){
      it1->second = max(it1->second, it2->second);
      range.erase(it2);
    } else {
      ++it1;
    }
  }

  int res = 0;
  for (list<pair<int, int> >::iterator it = range.begin();
       it != range.end(); ++it){
    //cout << "[" << it->first << "," << it->second << "]";
    res += it->second - it->first;
  }
  //cout << endl;
  
  //if (!p.empty()){
    //cout << "Count leftx:" << leftx << " line: " << p.size()
    //<< " area:" << res << endl;
  //}

  return res;
}

main()
{
  int m;
  while (cin >> m && m){
    vector<LINE> lines;
    lines.reserve(m);

    POINT points[101];
    for (int i = 0; i < m; ++i){
      double x, y;
      cin >> x >> y;
      points[i] = POINT(x, y);
    }
    points[m] = points[0];

    for (int i = 0; i < m; ++i){
      LINE l = make_pair(points[i], points[i + 1]);
      if (IsTate(l)){
	continue;
      }
      lines.push_back(l);
    }

    int answer = 0;
    for (int x = -2000; x < 2000; ++x){
      answer += CountArea(lines, x);
    }
    cout << answer << endl;
  }
}