#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pii pair<int, int>
const int mn = 5e5+5;
int n, m, k;
pii a[mn];
int val1[mn], val2[mn];
int q[mn];
void solve(){
cin >> n;
for(int i = 1; i <= n; i++) cin >> a[i].fi >> a[i].se;
sort(a + 1, a + n + 1);
for(int i = 1; i <= n; i++){
val1[i] = a[i].fi - a[i].se;
val2[i] = a[i].fi + a[i].se;
q[i] = 1;
}
priority_queue <pii, vector <pii>, greater<pii>> pq1;
priority_queue <pii> pq;
for(int i = 1; i <= n; i++){
while(!pq.empty() && pq.top().fi >= val1[i]){
pq.pop();
}
pq.push({val1[i], i});
// cout << pq.size() << '\n';
}
vector <int> xet;
while(pq.size()){
xet.push_back(pq.top().se);
pq.pop();
}
sort(xet.begin(), xet.end(), greater <int>());
for(auto i : xet){
while(!pq1.empty() && pq1.top().fi <= val2[i]){
pq1.pop();
}
pq1.push({val2[i], i});
}
cout << (int)pq1.size();
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int t = 1;
// cin >> t;
while(t--){
solve();
}
}
