#include <bits/stdc++.h> using namespace std; int main() { int n; cin >> n; vector<int> a(n + 1), b(n + 1); // 1-indexed for (int i = 1; i <= n; i++) cin >> a[i] >> b[i]; vector<int> dp(n + 1, 0); // all dp_i = 0 initially dp[1] = 1; for (int i = 2; i <= n; i++) { int prev = dp[i - 1]; int take = 0; if (i - a[i] - 1 >= 1) take = dp[i - a[i] - 1] + 1; else take = 1; // dp_j = 0 if j < 1, so 0 + 1 = 1 dp[i] = max(prev, take); } cout << dp[n]; return 0; }