#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define ln '\n'
const int N = 5e5 + 5;
array<int, 2> t[N];
int n, a[N], b[N], id[N];
// int id1[N], id2[N];
bool need[N];
priority_queue<int, vector<int>, greater<int>> pq;
void f(){
while (!pq.empty()) pq.pop();
for (int i = 0; i < n; i++){
while (!pq.empty()){
if (pq.top() > id[i]) break;
// dsu.unite(pq.top(), id[i]);
need[abs(pq.top())] = 0;
pq.pop();
}
pq.push(id[i]);
}
}
void solve(){
cin >> n;
for (int i = 0; i < n; i++) cin >> t[i][0] >> t[i][1];
sort(t, t+n);
auto x = unique(t, t+n);
n = distance(t, x);
for (int i = 0; i < n; i++){
a[i] = t[i][1] - t[i][0];
b[i] = t[i][1] + t[i][0];
}
// iota(id1, id1+n, 0); iota(id2, id2+n, 0);
// sort(id1, id1+n, [&](int x, int y){return a[x] == a[y]? x < y: a[x] < a[y];});
// sort(id2, id2+n, [&](int x, int y){return b[x] == b[y]? x > y: b[x] < b[y];});
// // reverse(id2, id2+n);
// for (int i = 0; i < n; i++) cout << id1[i] << ' ';
// cout << ln;
// for (int i = 0; i < n; i++) cout << id2[i] << ' ';
for (int i = 0; i < n; i++) need[i] = 1;
iota(id, id+n, 0);
sort(id, id+n, [&](int x, int y){return a[x] == a[y]? x < y: a[x] < a[y];});
f();
iota(id, id+n, 0);
sort(id, id+n, [&](int x, int y){return b[x] == b[y]? x > y: b[x] < b[y];});
for (int i = 0; i < n; i++) id[i] = -id[i];
f();
cout << accumulate(need, need+n, 0) << ln;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
// ll TT; cin >> TT;
// while (TT--) {solve();}
solve();
}
