//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define int long long
using namespace std;
struct node {
int color;
pair<int,int> sect;
node() = default;
node(int val,int l,int r) : color(val), sect(l,r) {}
};
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
vector <pair<int,int>> vec(n);
for (int i = 0;i < n;i++) {
cin >> vec[i].second >> vec[i].first;
}
sort(vec.begin(), vec.end());
int ans = 1;
for (int i = n - 2;i >= 0;i--) {
bool is_free = 0;
for (int j = i + 1;j < n;j++) {
int er = vec[j].first - vec[i].first;
int xr = abs(vec[j].second - vec[i].second);
if (xr <= er) {
is_free = 1;
}
}
if (!is_free) {
ans++;
}
}
cout << ans << '\n';
}
