#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#define ll long long
#define gcd __gcd
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define ts cin.tie(nullptr)->sync_with_stdio(false);
#define debug cout<<"HI"<<endl;
const int inf = 1e9;
const ll infll = 1e18;
using namespace std;
int main(){
ts
int n; cin >> n;
vector<pair<ll,ll>> v(n);
for(auto &[x,e]:v){
ll xi,ei;
cin >> xi >> ei;
x=xi-ei;
e=xi+ei;
}
sort(v.begin(),v.end(),[](auto &a,auto &b){
if(a.first!=b.first) return a.first<b.first;
return a.second>b.second;
});
int ans=0;
ll maxr=LLONG_MIN;
for(auto &[l,r]:v){
if(r>maxr){
ans++;
maxr=r;
}
}
cout << ans;
return 0;
}
