//JOI 2023 Final Round
#include<bits/stdc++.h>
using namespace std;
#define int long long
const int INF=1e18;
void solve(){
int n;
cin >> n;
vector<pair<int,int> > a(n);
for(int i=0; i<n; i++){
cin >> a[i].second >> a[i].first;
}
sort(a.begin(), a.end());
reverse(a.begin(), a.end());
set<pair<int,int> > given;
int ans=0;
for(int i=0; i<n; i++){
auto [e, x]=a[i];
auto r=given.upper_bound({x, e});
if(r!=given.end()){
auto [x2, e2]=*r;
if(e2-e >= x2-x) continue;
}
if(r!=given.begin()){
auto [x2, e2] =*prev(r);
if(e2-e >= x-x2) continue;
}
ans++;
given.insert({x, e});
}
cout << ans << "\n";
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<pair<int,int> > a(n);
vector<pair<pair<int,int> ,int> > sorted(n);
for(int i=0; i<n; i++){
int x, e;
cin >> x >> e;
a[i] = {x, e};
sorted[i]={{e-x, e+x}, i};
}
sort(sorted.begin(), sorted.end());
reverse(sorted.begin(), sorted.end());
int maxi=-INF;
int ans=0;
for(auto [val, i]: sorted){
auto [x, e] = a[i];
if(x+e <= maxi) continue;
maxi = x+e;
ans++;
}
cout << ans << "\n";
}
