// Goods things are coming, just keep believing 
 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace __gnu_pbds;
using namespace std;
 
 
#define FOR(i, x, n) for(ll i = x; i < n; i++) 
#define pb push_back
#define pf push_front
#define ll long long
#define hii cout << "hii" << endl
#define okay cout << "okay" << endl
// #define hey cout << "hey" << endl
#define pii pair<int, int>
#define pll pair<ll, ll>
#define mp make_pair
#define endl '\n'
#define ff first 
#define int long long
#define ss second
#define vi vector<int>
#define all(s) s.begin(), s.end()
#define si size()
 #define ld long double
#define INF 1000000000;
 
template <class T> ostream& operator << (ostream &os, const vector<T> &v) { for (T i : v) os << i << ' '; return os; }
template <class T> ostream& operator << (ostream &os, const set<T> &v) { for (T i : v) os << i << ' '; return os; }
template <class T, class S> ostream& operator << (ostream &os, const pair<T, S> &v) { os << v.first << ' ' << v.second; return os; }
template <class T, class S> ostream& operator << (ostream &os, const unordered_map<T, S> &v) { for (auto i : v) os << '(' << i.first << "=>" << i.second << ')' << ' '; return os; } 
 
 
 
#ifndef ONLINE_JUDGE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template <class Arg1> void __f(const char* name, Arg1&& arg1) { cerr << name << " : " << arg1 << endl; }
    template <class Arg1, class... Args>
    void __f(const char* names, Arg1&& arg1, Args&&... args) {
        const char* sep = strchr(names + 1, ',');
        cerr.write(names, sep - names) << " : " << arg1 << "  ";
        __f(sep + 1, args...);
    }
#else
#define trace(...) 0
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define _CRT_SECURE_NO_WARNINGS
#endif // ifndef ONLINE_JUDGE
 
typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
 
 
 
const int N = 5e5 + 5;
const int LG = 20;
const int mod = 1e9 + 7;

int arr[N];
int dp[N];
int sub[N];
int n, c;
vector<pair<int, int>> v;
ll a[N] = {0};

int ans = 0;
int l[N], r[N];
map<int, set<pair<int, int> > > events;
set<pair<int, int> > have;
vector<int> toRemove;

int f(int n)
{
	int k = 1;
	for(int i = 1; i <= n; i++)
	{
		l[i] = v[i - 1].first;
		r[i] = v[i - 1].second;
		events[l[i]].insert({r[i] + 1, i});
		events[r[i] + 1].insert({-1, i});
	}	
	int cnt = 0;	
	for(auto &it:events)
	{
		for(auto &cur:it.second)
			if(cur.first < 0)
				cnt--;
		for(auto &cur:it.second)
		{
			if(cur.first > 0)
			{
				cnt++;
				have.insert(cur);
			}
		}
		while(cnt > k)
		{
			ans++;
			cnt--;
			pair<int, int> lastEnd = *have.rbegin();			
			have.erase(lastEnd);
			toRemove.push_back(lastEnd.second);
			events[lastEnd.first].erase({-1, lastEnd.second});
		}
	}
	return toRemove.size();
}


void solve()
{
	int n;
	cin >> n;
	for(int i = 0; i < n; i++)
	{
		int x, xx;
		cin >> x >> xx;
		int l = x - xx + 1;
		int r = x + xx;
		v.push_back({l, r});
	}
	cout << n - f(n);
}
 
int32_t main()
{
	ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

	int t = 1;
	// cin >> t;
	while(t--)
	{
		solve();
	}
}

Measured memory_bytes: 48240