#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
const int inf = 1e18;
signed main(){
ios::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
int n;
cin >> n;
vector<pair<int, int>> v;
for(int i = 1, x, e; i <= n; ++i){
cin >> x >> e;
v.push_back({x - e, x + e});
}
// xi - xj <= ei - ej
// xi - ei <= xj - ej
// xi + ei >= ej + xj
sort(all(v), [&](pair<int, int> x, pair<int, int> y){
if(x.first == y.first) return x.second > y.second;
return x.first < y.first;
});
//v.erase(unique(v.begin(), v.end()), v.end());
vector<int> dp(n + 5, 1);
for(int i = 0; i < n; ++i){
for(int j = i - 1; j >= 0; --j){
if(v[j].second < v[i].second){
dp[i] = max(dp[i], dp[j] + 1);
}
}
}
cout << *max_element(all(dp)) << "\n";
return 0;
}
