/*
 * author:  ADMathNoob
 * created: 05/09/24 12:12:19
 * problem: https://qoj.ac/problem/2295
 */

/*
Comments about problem:


*/

#include <bits/stdc++.h>

using namespace std;

#ifdef _DEBUG
#include "debug.h"
#else
#define debug(...) 42
#endif

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  if (n == 1) {
    cout << 4 << '\n';
    return 0;
  }
  vector<int> x(n), y(n);
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i];
  }
  for (int rot = 0; rot < 2; rot++) {
    vector<int> d(n);
    for (int i = 0; i < n; i++) {
      d[i] = x[i] - y[i];
    }
    if (count(d.begin(), d.end(), d[0]) == n) {
      int minX = *min_element(x.begin(), x.end());
      int maxX = *max_element(x.begin(), x.end());
      int delta = maxX - minX;
      cout << 2 * delta + 5 << '\n';
      return 0;
    }
    for (int i = 0; i < n; i++) {
      x[i] = -x[i];
    }
  }
  const int inf = 1e9;
  int ans = 0;
  for (int rot = 0; rot < 4; rot++) {
    // build the top-right diagonal
    int y1 = *max_element(y.begin(), y.end());
    int x2 = *max_element(x.begin(), x.end());
    int x1 = inf;
    int y2 = -inf;
    for (int i = 0; i < n; i++) {
      if (y[i] == y1) {
        x1 = min(x1, x[i]);
      }
      if (x[i] == x2) {
        y2 = max(y2, y[i]);
      }
    }
    y1 += 1;
    x2 += 1;
    
    vector<int> order(n);
    iota(order.begin(), order.end(), 0);
    sort(order.begin(), order.end(), [&](int i, int j) {
      return x[i] > x[j];
    });
    int maxY = -inf;
    int beg = 0;
    vector<pair<int, int>> suf;
    while (beg < n) {
      int end = beg;
      while (end < n && x[order[end]] == x[order[beg]]) ++end;
      for (int i = beg; i < end; i++) {
        maxY = max(maxY, y[order[i]]);
      }
      suf.emplace_back(x[order[beg]], maxY);
      beg = end;
    }
    reverse(suf.begin(), suf.end());
    // debug(suf);

    auto Exists = [&](int x0, int y0) {
      // does there exist a point (x, y) with x >= x0, y >= y0?
      auto it = lower_bound(suf.begin(), suf.end(), make_pair(x0, -inf));
      if (it == suf.end()) return false;
      return it->second >= y0;
    };
    
    int cx = x1, cy = y1;
    int res = 0;
    while (cx != x2) {
      assert(!Exists(cx, cy));
      if (Exists(cx + 1, cy - 1)) {
        cx += 1;
      } else {
        cx += 1;
        cy -= 1;
      }
      res += 1;
      // debug(cx, cy);
    }
    assert(cy >= y2);
    res += cy - y2;
    // debug(res);
    ans += res;
    
    // next iteration
    for (int i = 0; i < n; i++) {
      int nx = y[i];
      int ny = -x[i];
      x[i] = nx;
      y[i] = ny;
    }
  }
  cout << ans << '\n';
  return 0;
}