//cf meowcneil; t.me/macneilbot
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <bitset>
#include <iterator>
#include <iomanip>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <random>
#include <cassert>
using namespace std;
#define int long long
#define pb push_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define f(a) for(int i = 0; i<a; ++i)
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef string str;
typedef vector<str> vestr;
typedef vector<int> vei;
typedef vector<vector<int>> veve;
void solve() {
int n;
cin >> n;
vector<pair<int, int>> a(n);
for (int i = 0; i < n; ++i) cin >> a[i].first >> a[i].second;
sort(all(a));
vector<bool> used(n, 1);
deque<int> cur;
cur.push_back(0);
for (int i = 1; i < n; ++i) {
while(cur.size()) {
int pused = cur.back();
if (a[i].first - a[pused].first <= a[i].second - a[pused].second) {
used[pused] = 0;
cur.pop_back();
}
else if (a[i].first - a[pused].first <= a[pused].second - a[i].second) {
used[i] = 0;
break;
}
else {
cur.push_back(i);
break;
}
}
if (cur.size() == 0) cur.push_back(i);
}
cout << cur.size();
}
signed main() {
int tc = 1;
#ifdef LOCAL
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
// cin >> tc;
#else
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// cin >> tc;
#endif
for (int t = 1; t <= tc; t++) {
// cout << "Case #" << t << ": ";
solve();
}
}
