#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define bitcount __builtin_popcountll
using namespace std;
using namespace __gnu_pbds;
using namespace chrono;
struct segtree {
vector<int> tree;
int offset = 1;
segtree(int n) {
while (offset < n) offset <<= 1;
tree.resize(offset << 1);
}
void update(int i, int x) {
tree[i += offset] = x;
while (i >>= 1) tree[i] = max(tree[2*i], tree[2*i + 1]);
}
int _query(int v, int l, int r, int ql, int qr) {
if (ql <= l && r <= qr) return tree[v];
if (qr < l || r < ql) return 0;
int mid = (l+r) >> 1;
return max({
_query(2*v, l, mid, ql, qr),
_query(2*v + 1, mid + 1, r, ql, qr)
});
}
int query(int l, int r) {
if (r < l) return 0;
return _query(1, 0, offset - 1, l, r);
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr), cout.tie(nullptr);
int n; cin >> n;
int l[n], r[n];
for (int i = 0; i < n; cin >> l[i] >> r[i++]);
int dp[n];
vector<int> upd[n];
segtree s(n);
for (int i = 0; i < n; i++) {
dp[i] = s.query(0, i - l[i] - 1) + 1;
if (i + r[i] < n) upd[i + r[i]].push_back(i);
for (int ind : upd[i]) {
s.update(ind, dp[ind]);
}
}
cout << *max_element(dp, dp + n);
}
