#include <bits/stdc++.h>
#define int long long
using namespace std;
const long long N = 5e5 + 5;
struct home
{
int e, x, idx;
};
vector<int> graph[N];
home a[N];
bool vis[N];
void solve()
{
int n;
cin >> n;
vector<pair<int, int>> stak;
set<int> aa, bb;
for (int i = 0; i < n; i++)
{
cin >> a[i].x >> a[i].e;
bb.insert(a[i].e);
aa.insert(a[i].x);
a[i].idx = i + 1;
}
if (bb.size() == 1)
{
// cout << "YEAH, done 10 more points";
cout << aa.size() << endl;
return;
}
sort(a, a + n, [&](home a, home b)
{if(a.x==b.x)
return a.e < b.e;
return a.x < b.x; });
int u, v;
set<pair<int, int>> edges;
for (int i = 0; i < n; i++)
{
u = a[i].idx;
int e = a[i].x - a[i].e;
// cout << e << endl;
while (stak.size() and e <= stak.back().first)
{
v = stak.back().second;
edges.insert({u, v});
stak.pop_back();
}
// e = +a[i].x - a[i].e;
stak.push_back({e, a[i].idx});
}
stak.clear();
sort(a, a + n, [&](home a, home b)
{if(a.x==b.x)
return a.e > b.e;
return a.x > b.x; });
for (int i = 0; i < n; i++)
{
u = a[i].idx;
int e = a[i].x + a[i].e;
while (stak.size() and e >= stak.back().first)
{
v = stak.back().second;
edges.insert({u, v});
stak.pop_back();
}
stak.push_back({e, a[i].idx});
}
vector<int> indeg(n + 1, 0);
for (auto i : edges)
{
// cout << i.first << " " << i.second << endl;
graph[i.first].push_back(i.second);
indeg[i.second]++;
}
queue<int> q;
for (int i = 0; i < n; i++)
{
if (indeg[i + 1] == 0)
{
q.push(i + 1);
// cout << " pushed " << i + 1 << endl;
}
}
int ans = q.size();
// cout << ans << endl;
while (q.size())
{
int k = q.front();
// cout << " now visiting " << k << endl;
q.pop();
if (vis[k])
continue;
vis[k] = 1;
for (int i : graph[k])
{
if (vis[i] == 0)
q.push(i);
}
}
for (int i = 1; i <= n; i++)
{
if (!vis[i])
{
// cout << "not visited i " << i << endl;
ans++;
q.push(i);
while (q.size())
{
int k = q.back();
q.pop();
if (vis[k])
continue;
vis[k] = 1;
for (int i : graph[k])
{
if (!vis[i])
q.push(i);
}
}
}
}
cout << ans << endl;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
int t = 1;
// cin >> t;
for (int i = 1; i <= t; i++)
{
// cout << "Case #" << i << ':' << ' ';
solve();
cout << endl;
}
return 0;
}
