Arkady has got an infinite plane painted in color 0. Then he draws n rectangles filled with paint with sides parallel to the Cartesian coordinate axes, one after another. The color of the i-th rectangle is i (rectangles are enumerated from 1 to n in the order he draws them). It is possible that new rectangles cover some of the previous ones completely or partially.

Count the number of different colors on the plane after Arkady draws all the rectangles.

Input

The first line contains a single integer n (1 ≤ n ≤ 100 000) — the number of rectangles.

The i-th of the next n lines contains 4 integers x_1, y_1, x_2 and y_2 (-10^9 ≤ x_1 < x_2 ≤ 10^9, -10^9 ≤ y_1 < y_2 ≤ 10^9) — the coordinates of corners of the i-th rectangle.

Output

In the single line print the number of different colors in the plane, including color 0.

Examples

Input

5
-1 -1 1 1
-4 0 0 4
0 0 4 4
-4 -4 0 0
0 -4 4 0


Output

5

Input

4
0 0 4 4
-4 -4 0 0
0 -4 4 0
-2 -4 2 4


Output

5

Note

<image> That's how the plane looks in the first sample

<image> That's how the plane looks in the second sample

0 = white, 1 = cyan, 2 = blue, 3 = purple, 4 = yellow, 5 = red. 
#include <bits/stdc++.h>
using namespace std;
using LD = long double;
using PLL = pair<long long, long long>;
using VII = vector<pair<int, int> >;
template <class T>
bool power_2(T v) {
  static_assert(std::is_integral<T>::value, "type should be integral");
  return v && !(v & (v - 1));
}
template <class T>
istream& operator>>(istream& st, vector<T>& container) {
  for (auto& u : container) st >> u;
  return st;
}
template <class T>
ostream& operator<<(ostream& st, const vector<T>& container) {
  for (auto& u : container) st << u << '\n';
  return st;
}
template <class T, size_t N>
istream& operator>>(istream& st, array<T, N>& container) {
  for (auto& u : container) st >> u;
  return st;
}
template <class T, size_t N>
ostream& operator<<(ostream& st, const array<T, N>& container) {
  for (auto u : container) st << u << ' ';
  return st;
}
template <class T, class U>
istream& operator>>(istream& st, pair<T, U>& p) {
  st >> p.first >> p.second;
  return st;
}
template <class T, class U>
ostream& operator<<(ostream& st, pair<T, U> p) {
  st << p.first << ' ' << p.second;
  return st;
}
template <class T, class U, class V>
pair<T, U> operator*(pair<T, U> p, V val) {
  return {p.first * val, p.second * val};
}
template <class T, class U, class V>
pair<T, U> operator/(pair<T, U> p, V val) {
  return {p.first / val, p.second / val};
}
template <class T, class U>
pair<T, U> operator-(pair<T, U> a, pair<T, U> b) {
  return {a.first - b.first, a.second - b.second};
}
template <class T, class U>
pair<T, U> operator+(pair<T, U> a, pair<T, U> b) {
  return {a.first + b.first, a.second + b.second};
}
template <class T>
T dotProduct(pair<T, T> a, pair<T, T> b) {
  return a.first * b.first + a.second * b.second;
}
template <class T>
T crossProduct(pair<T, T> a, pair<T, T> b) {
  return a.first * b.second - a.second * b.first;
}
template <class T>
T lengthPow(pair<T, T> a) {
  return a.first * a.first + a.second * a.second;
}
template <class T>
LD length(pair<T, T> a) {
  return sqrt(lengthPow(a));
}
int const inf = 1e9 + 7;
int const N = 1e5 + 7;
int const M = 1 << 18;
struct Node {
  priority_queue<int> rectangles;
  int max, min;
  Node() : max(-1), min(0) {}
};
bitset<N> seen, erased;
Node segTree[2 * M];
void update(int v) {
  auto& que = segTree[v].rectangles;
  int& minVal = segTree[v].min;
  int& maxVal = segTree[v].max;
  while (!que.empty() && erased[que.top()]) {
    que.pop();
  }
  int maxInChildren = -1;
  if (v < M) maxInChildren = max(segTree[v + v].max, segTree[v + v + 1].max);
  int minInChildren = 0;
  if (v < M) minInChildren = min(segTree[v + v].min, segTree[v + v + 1].min);
  int maxInNode = -1;
  if (!que.empty()) maxInNode = que.top();
  if (maxInNode > maxInChildren) {
    if (seen[maxInNode] || maxInNode < minInChildren)
      maxVal = -1;
    else
      maxVal = maxInNode;
  } else {
    maxVal = maxInChildren;
  }
  minVal = max(maxInNode, minInChildren);
}
void addSegment(int col, int a, int b, bool add, int v = 1, int l = 0,
                int p = M) {
  if (b <= l || p <= a) return;
  if (a <= l && p <= b) {
    if (add) {
      segTree[v].rectangles.push(col);
    }
    update(v);
    return;
  }
  int mid = (l + p) / 2;
  addSegment(col, a, b, add, 2 * v, l, mid);
  addSegment(col, a, b, add, 2 * v + 1, mid, p);
  update(v);
}
int x1[N], x2[N], Y1[N], Y2[N];
map<int, int> newCoordsX, newCoordsY;
vector<pair<int, int> > events[2 * N];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> x1[i] >> Y1[i] >> x2[i] >> Y2[i];
    newCoordsX[x1[i]] = 0;
    newCoordsX[x2[i]] = 0;
    newCoordsY[Y1[i]] = 0;
    newCoordsY[Y2[i]] = 0;
  }
  int j = 0;
  for (auto& u : newCoordsY) u.second = j++;
  j = 0;
  for (auto& u : newCoordsX) u.second = j++;
  for (int i = 0; i < n; ++i) {
    x1[i] = newCoordsX[x1[i]];
    x2[i] = newCoordsX[x2[i]];
    Y1[i] = newCoordsY[Y1[i]];
    Y2[i] = newCoordsY[Y2[i]];
    events[x1[i]].push_back({i, 1});
    events[x2[i]].push_back({i, 0});
  }
  for (int i = 0; i < 2 * n; ++i) {
    for (auto u : events[i]) {
      int c = u.first;
      int t = u.second;
      if (t == 0) erased[c] = 1;
      addSegment(c, Y1[c], Y2[c], t);
    }
    while (segTree[1].max >= segTree[1].min) {
      int id = segTree[1].max;
      seen[id] = 1;
      addSegment(id, Y1[id], Y2[id], 0);
    }
  }
  int res = 1;
  for (int i = 0; i < n; ++i) {
    if (seen[i]) ++res;
  }
  cout << res << '\n';
}
