#include <bits/stdc++.h> using namespace std; #define int long long const int INF = 1e18; const int MOD = 1e9+7; const int MAXN = 2e5; int n, m; int arr[MAXN+5][5]; int dp[MAXN+5]; priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq; void mulaidarinol(){} void solve(){ cin >> n; for(int i = 1; i <= n; i++){ cin >> arr[i][0] >> arr[i][1]; arr[i][0] = min(i - 1, arr[i][0]); arr[i][1] = min(n - i, arr[i][1]); } vector<pair<int, int>> v; for(int i = 1; i <= n; i++) v.push_back({i - arr[i][0], i}); sort(v.begin(), v.end()); int mx = 0; for(auto [kiri, idx] : v){ // cerr << "idx : " << idx << endl; while(!pq.empty() && pq.top().first < idx){ // cerr << idx << " : " << pq.top().second << endl; mx = max(dp[pq.top().second], mx); pq.pop(); } // cerr << kiri - 1 + arr[kiri-1][1] << ' ' << idx << endl; if(kiri - 1 + arr[kiri-1][1] < idx) mx = max(dp[kiri - 1], mx); dp[idx] = mx + 1; pq.push({idx + max(arr[idx][1], 1ll), idx}); } int ans = 0; for(int i = 1; i <= n; i++){ ans = max(dp[i], ans); // cerr << "dp[" << i << "] : " << dp[i] << endl; } cout << ans << endl; } signed main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int tc = 1; // cin >> tc; while(tc--){ // mulaidarinol(); solve(); } return 0; }