#include<bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
int n, ft[N];
void update(int x, int d) {
while(x <= n) ft[x] = max(ft[x], d), x += (x & -x);
}
int get(int l)
{
int ans = 0;
while(l > 0) ans = max(ans, ft[l]), l -= (l & -l);
return ans;
}
int main()
{
int ans = 0;
cin >> n;
set<vector<int> > up;
for(int i = 1; i <= n; i ++)
{
while(up.size() && up.begin()->at(0) < i)
{
update(up.begin()->at(1), up.begin()->at(2));
up.erase(up.begin());
}
int l, r;
cin >> l >> r;
int sol = 1 + get(i - l - 1);
ans = max(ans, sol);
up.insert({i + r, i, sol});
}
cout << ans << endl;
return 0;
}
