#include <bits/stdc++.h> using namespace std; #define MOD1 1000000007 #define MOD2 998244353 #define fir first #define sec second #define pushf push_front #define pushb push_back #define popf pop_front #define popb pop_back #define mp make_pair #define all(a) a.begin(), a.end() #define lbound(v, x) lower_bound(all(v), x) - v.begin() #define ubound(v, x) upper_bound(all(v), x) - v.begin() #define chmax(a, b) a = max(a, b) #define chmin(a, b) a = min(a, b) #define FOR1(a) for (int _ = 0; _ < (a); ++_) #define FOR2(i, a) for (int i = 0; i < (a); ++i) #define FOR3(i, a, b) for (int i = (a); i < (b); ++i) #define RFOR1(a) for (int _ = (a)-1; _ >= 0; --_) #define RFOR2(i, a) for (int i = (a)-1; i >= 0; --i) #define RFOR3(i, a, b) for (int i = (b)-1; i >= (a); --i) #define overload3(a, b, c, d, ...) d // Always choose the fourth argument to call. Hence, which function to call is determined by the number of given arguments. #define REP(...) overload3(__VA_ARGS__, FOR3, FOR2, FOR1)(__VA_ARGS__) #define RREP(...) overload3(__VA_ARGS__, RFOR3, RFOR2, RFOR1)(__VA_ARGS__) typedef long long ll; typedef pair<int, int> pii; typedef vector<int> vi; typedef pair<ll, ll> pll; typedef vector<ll> vll; typedef vector<bool> vb; typedef vector<char> vc; typedef vector<string> vs; typedef vector<pii> vpii; typedef vector<pll> vpll; typedef vector<vi> vvi; typedef vector<vll> vvll; typedef vector<vb> vvb; typedef vector<vc> vvc; typedef vector<vpii> vvpii; typedef vector<vpll> vvpll; typedef queue<int> qi; typedef queue<ll> qll; typedef queue<pii> qpii; typedef queue<pll> qpll; typedef deque<int> dqi; typedef deque<ll> dqll; typedef deque<pii> dqpii; typedef deque<pll> dqpll; typedef priority_queue<int> pqi; typedef priority_queue<ll> pqll; typedef priority_queue<pii> pqpii; typedef priority_queue<pll> pqpll; typedef priority_queue<int, vi, greater<int> > r_pqi; typedef priority_queue<ll, vll, greater<ll> > r_pqll; typedef priority_queue<pii, vpii, greater<pii> > r_pqpii; typedef priority_queue<pll, vpll, greater<pll> > r_pqpll; typedef pair<pll, pll> pllll; pll calc(pll a, pll b) { if(a.fir == b.fir) { return mp(a.fir, a.sec + b.sec); } else { return max(a, b); } } struct node { int n; vpll val; node(int size = 0) : n(size) { val.assign(4 * n, mp(0, 0)); } void update(int q, pll v, int ind = 1, int l = 0, int r = -1) { if(r == -1) r = n-1; if(q > r || l > q) return; if(q <= l && r <= q) { val[ind] = v; return; } int mid = (l + r) / 2; update(q, v, 2 * ind, l, mid); update(q, v, 2 * ind + 1, mid + 1, r); val[ind] = calc(val[2 * ind], val[2 * ind + 1]); } pll query(int ql, int qr, int ind = 1, int l = 0, int r = -1) { if(r == -1) r = n-1; if(ql > r || l > qr) return mp(0, 0); if(ql <= l && r <= qr) return val[ind]; int mid = (l + r) / 2; return calc(query(ql, qr, 2 * ind, l, mid), query(ql, qr, 2 * ind + 1, mid + 1, r)); } }; int main() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n; cin>>n; vector<array<ll, 4>> arr(n); vll dis; dis.reserve(4*n); REP(i, n) { REP(j, 4) { cin>>arr[i][j]; dis.pushb(arr[i][j]); } } sort(all(dis)); dis.erase(unique(all(dis)), dis.end()); REP(i, n) { REP(j, 4) { arr[i][j] = lbound(dis, arr[i][j])+1; } } sort(all(arr)); node root(4*n+1); priority_queue<pllll, vector<pllll>, greater<pllll>> pq; root.update(0, mp(0, 1)); REP(i, n) { auto [a, b, c, d] = arr[i]; while(!pq.empty() && pq.top().fir.fir < a) { root.update(pq.top().fir.sec, pq.top().sec); pq.pop(); } pll cur = root.query(0, c-1); cur.fir++; // cerr<<cur<<endl; pq.push(mp(mp(b, d), cur)); } while(!pq.empty()) { root.update(pq.top().fir.sec, pq.top().sec); pq.pop(); } pll ans = root.query(0, 4*n+1); cout<<ans.fir<<endl; }