#include <bits/stdc++.h>

using namespace std;

#define loop(i,n) for(int i=0; i<n; i++)
#define all(a) a.begin(),a.end()
#define fr first
#define sc second

int INF=1e9;

struct node{
    int he,l,r,ch;
    node ()
    {
        he = ch = INF;
    }
};

const int n = 5e5 * 4;
node tree[n];
pair <pair <int,int> , pair <int,int> > ar[50000];

void push(int v)
{
    if (tree[v].ch != INF && tree[v].l!=tree[v].r)
    {
        tree[v*2].he = tree[v].ch;
        tree[v*2+1].he = tree[v].ch;
        tree[v*2].ch = tree[v].ch;
        tree[v*2+1].ch = tree[v].ch;
        tree[v].ch = INF;
    }
}

void build_tree(int v, int l, int r)
{
    if (l > r) return;
    tree[v].l = l; tree[v].r = r;
    if (l == r)
    {
        tree[v].he = -1;
        return;
    }
    int mid = (l + r)/2;
    build_tree(v*2, l, mid);
    build_tree(v*2+1, mid+1, r);
    tree[v].he = max (tree[v*2].he, tree[v*2+1].he);
}

int find_max(int v, int l)
{
    push(v);
    if (tree[v].l > l || tree[v].r < l) return -1e5;
    if (tree[v].l == tree[v].r && tree[v].l == l) return tree[v].he;
    return max(find_max(v*2, l),find_max(v*2+1, l));
}

void upd(int v, int l, int r, int nw)
{
    //cout << tree[v].ch;
    push(v);
    if (tree[v].l > r || tree[v].r < l) return;
    if (tree[v].l >= l && tree[v].r <= r)
    {
        tree[v].ch = nw;
        tree[v].he = nw;
        return;
    }
    //int mid = (l+r)/2;
    upd(v*2, l , r , nw);
    upd(v*2+1, l , r , nw);
    tree[v].he = max(tree[v*2].he, tree[v*2+1].he);
}

signed main()
{
    int n;
    cin >> n;
    loop(i,50001)
    {
        ar[i].fr.fr = INF;
        ar[i].fr.sc = INF;
        ar[i].sc.fr = INF;
        ar[i].sc.sc = INF;
    }
    loop(i,n)
    {
        int x1,y1,x2,y2;
        cin >> x1 >> y1 >> x2 >> y2;
        ar[i].fr.fr = x1;
        ar[i].fr.sc = x2;
        ar[i].sc.fr = y1;
        ar[i].sc.sc = y2;
    }

    int ans=0;
    sort(ar, ar + 50001);
    build_tree(1, 0, 5e5);
    loop(i,n)
    {
        if (find_max(1,ar[i].sc.fr) < ar[i].fr.fr)
        {
            ans++;
            upd(1, ar[i].sc.fr, ar[i].sc.sc, ar[i].fr.sc);
        }
    }
    cout << ans;
}