#include <bits/stdc++.h>
#define all(a) (a).begin(), (a).end()
using namespace std;
int main() {
int n; cin >> n;
pair<int,int> a[n];
// x[j] - x[i] <= e[i] - e[j]
// x[j] + e[j] <= e[i] + x[i]
//
// x[i] - x[j] <= e[i] - e[j]
// e[j] - x[j] <= e[i] - x[i]
//
// X[j] <= X[i]
// Y[j] <= Y[i]
for (auto& [x, y] : a) {
int pos, inf; cin >> pos >> inf;
x = inf + pos;
y = -(inf - pos);
}
sort(a, a+n, greater<>());
deque<int> lis;
for (auto [x, y] : a) {
y = -y;
auto it = lower_bound(lis.rbegin(), lis.rend(), y);
if (it == lis.rend())
lis.push_front(y);
else
*it = y;
}
cout << lis.size();
}
