#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define F first
#define S second
#define pb push_back
#define pii pair<int,int>
const int N = 5e5 + 5;
const int inf = 2e9 + 246;
struct SegTree {
vector<pii> st;
int n;
SegTree() {}
SegTree(int n) : n(n) {
st.assign(4 * n + 5, {inf, inf});
}
void update(int id, int l, int r, int i, int x) {
if (l == r) {
st[id] = {x, i};
return;
}
int mid = (l + r) / 2;
if (i <= mid) update(id * 2, l, mid, i, x);
else update(id * 2 + 1, mid + 1, r, i, x);
st[id] = min(st[id * 2], st[id * 2 + 1]);
}
pii get(int id, int l, int r, int u, int v) {
if (v < l || r < u) {
return {inf, inf};
}
if (u <= l && r <= v) {
return st[id];
}
int mid = (l + r) / 2;
return min(get(id * 2, l, mid, u, v), get(id * 2 + 1, mid + 1, r, u, v));
}
} st_lower, st_higher;
int n;
pii a[N];
int x[N];
int del[N];
int pos[N];
pii b[N];
int t;
bool cmp(pii x, pii y) {
return x.S < y.S;
}
signed main(){
ios_base::sync_with_stdio(false) ;
cin.tie(0) ; cout.tie(0) ;
if (fopen("INP.INP" ,"r")) {
freopen("INP.INP" ,"r" , stdin) ;
freopen("OUT.OUT" , "w" , stdout) ;
}
cin >> t;
for (int i = 1; i <= t; i++) {
cin >> b[i].F >> b[i].S;
}
sort(b + 1, b + 1 + t);
int n = 0;
for (int i = 1; i <= t; i++) {
if (i == t || b[i].F != b[i + 1].F) a[++n] = b[i];
}
// cout << n << '\n';
// for (int i = 1; i <= n; i++) {
// cout << a[i].F << ' ' << a[i].S << '\n';
// }
vector<pii> compressed;
for (int i = 1; i <= n; i++) {
cin >> a[i].F >> a[i].S;
compressed.pb({a[i].F, a[i].S});
}
sort(compressed.begin(), compressed.end());
sort(a + 1, a + 1 + n, cmp);
for (int i = 1; i <= n; i++) {
x[i] = upper_bound(compressed.begin(), compressed.end(), a[i]) - compressed.begin();
}
for (int i = 1; i <= n; i++) {
pos[x[i]] = i;
}
st_lower = SegTree(n);
st_higher = SegTree(n);
for (int i = 1; i <= n; i++) {
st_lower.update(1, 1, n, x[i], a[i].S - a[i].F);
st_higher.update(1, 1, n, x[i], a[i].F + a[i].S);
}
int res = 0;
for (int i = n; i >= 1; i--) {
if (del[i]) continue;
res++;
del[i] = 1;
st_lower.update(1, 1, n, x[i], inf);
st_higher.update(1, 1, n, x[i], inf);
while(1) {
pii tmp = st_lower.get(1, 1, n, 1, x[i]);
// cout << i << ' ' << tmp.F << ' ' << tmp.S << endl;
if (tmp.F > a[i].S - a[i].F) break;
del[pos[tmp.S]] = 1;
st_lower.update(1, 1, n, tmp.S, inf);
st_higher.update(1, 1, n, tmp.S, inf);
}
while(1) {
pii tmp = st_higher.get(1, 1, n, x[i], n);
// cout << i << ' ' << tmp.F << ' ' << tmp.S << endl;
if (tmp.F > a[i].F + a[i].S) break;
del[pos[tmp.S]] = 1;
st_lower.update(1, 1, n, tmp.S, inf);
st_higher.update(1, 1, n, tmp.S, inf);
}
}
cout << res;
}
