#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Node = array<int, 2>;
#define mid ((l+r) >> 1)
const int INF = 1e9;
int n, a[200200], b[200200], c[200200], d[200200], p[200200], chk[200200];
map<int, int> mp[200200];
int lz[800800];
Node t[800800];
void lazy_update(int node, int l, int r) {
if(lz[node]) {
t[node][0] += lz[node];
if(l != r) lz[node*2] += lz[node], lz[node*2+1] += lz[node];
lz[node] = 0;
}
}
void update(int nl, int nr, int val, int node = 1, int l = 1, int r = n) {
lazy_update(node, l, r);
if(nr < l || r < nl) return;
if(nl <= l && r <= nr) {
lz[node] += val;
lazy_update(node, l, r);
return;
}
update(nl, nr, val, node*2, l, mid), update(nl, nr, val, node*2+1, mid+1, r);
t[node] = min(t[node*2], t[node*2+1]);
}
int ans;
void match(int x, int y) {
if(a[x] == c[y]) ans++;
auto id = lower_bound(p+1, p+1+n, y) - p;
chk[y] = 1, mp[c[y]].erase(d[y]);
update(x, x, INF), update(id, n, -1);
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for(int i=1;i<=n;i++) cin >> a[i] >> b[i];
for(int i=1;i<=n;i++) cin >> c[i] >> d[i];
for(int i=1;i<=n;i++) {
p[i] = p[i-1];
while(p[i] < n && d[p[i]+1] >= b[i]) p[i]++;
mp[c[i]][d[i]] = i;
}
for(int i=1;i<=4*n;i++) t[i] = {INF, 0};
for(int i=1, j=1;i<=n;i++) {
while(t[1][0] == 1) {
int u = t[1][1];
while(chk[j]) j++;
match(u, j);
}
auto it = mp[a[i]].lower_bound(b[i]);
if(it != mp[a[i]].end()) {
match(i, it->second);
continue;
}
update(i, i, p[i]-INF);
}
cout << n-ans;
}
