#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 2e5 + 5;
int st[4 * maxn];
void update(int id, int l, int r, int i, int val){
if (l > i || r < i || l > r) return;
if (l == r){
st[id] = max(st[id], val);
return;
}
int mid = (l + r) / 2;
update(2 * id, l, mid, i, val);
update(2 * id + 1, mid + 1, r, i, val);
st[id] = max(st[2 * id], st[2 * id + 1]);
}
int get(int id, int l, int r, int x, int y){
if(l > y || r < x) return 0;
if(l >= x && r <= y) return st[id];
int mid = (l + r) / 2;
return max(get(2 * id, l, mid, x, y), get(2 * id + 1, mid + 1, r, x , y));
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n; cin >> n;
vector<int> a(n + 1), b(n + 1), sweep1[n + 2], sweep2[n + 2];
for(int i = 1; i <= n; i++){
cin >> a[i] >> b[i];
sweep1[min(i + b[i], n) + 1].push_back(i);
sweep2[i].push_back(max(1ll, i - a[i]) - 1);
}
vector<int> dp(n + 1, 1);
for(int i = 1; i <= n; i++){
for(int j: sweep1[i]) update(1, 1, n, j, dp[j]);
for(int j: sweep2[i]) dp[i] = max(dp[i], get(1, 1, n, 1, j) + 1);
}
cout << *max_element(dp.begin(), dp.end());
}
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