#include <bits/stdc++.h>
#define int long long
using namespace std;
const long long N = 2e5 + 5;
struct home
{
int e, x;
};
home a[N];
void solve()
{
int n;
cin >> n;
vector<int> stak;
for (int i = 0; i < n; i++)
{
cin >> a[i].x >> a[i].e;
}
sort(a, a + n, [&](home a, home b)
{ return a.x < b.x; });
for (int i = 0; i < n; i++)
{
int e = a[i].x - a[i].e;
// cout << e << endl;
while (stak.size() and e <= stak.back())
{
stak.pop_back();
}
// e = +a[i].x - a[i].e;
stak.push_back(e);
}
cout << stak.size() << 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;
}
