#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 1;
int n, l[maxn], r[maxn];
int ans, dp[maxn];
int st[maxn << 2];
vector<int> que[maxn];
void update(int i, int tl, int tr, int p, int v) {
if (tl == tr) {
st[i] = v; return;
}
int x = (i << 1) + 1, y = x + 1;
int tm = (tl + tr) >> 1;
if (p <= tm) update(x, tl, tm, p, v);
else update(y, tm + 1, tr, p, v);
st[i] = max(st[x], st[y]);
}
int query(int i, int tl, int tr, int l, int r) {
if (tl == l && r == tr) return st[i];
int x = (i << 1) + 1, y = x + 1;
int tm = (tl + tr) >> 1;
if (r <= tm) return query(x, tl, tm, l, r);
if (tm < l) return query(y, tm + 1, tr, l, r);
return max(
query(x, tl, tm, l, tm),
query(y, tm + 1, tr, tm + 1, r)
);
}
int main() {
cin >> n;
for (int i = 1; i <= n; i++)
cin >> l[i] >> r[i];
for (int i = 1; i <= n; i++) {
int ll = i - l[i], rr = i + r[i];
dp[i] = query(0, 0, n, 0, max(0, ll - 1)) + 1;
ans = max(ans, dp[i]);
if (rr <= n) que[rr].push_back(i);
for (int j : que[i]) {
update(0, 0, n, j, dp[j]);
}
}
cout << ans << endl;
return 0;
}
