#include <bits/stdc++.h>
#define l first;
#define r second;
using namespace std;
int solve1()
{
int K;
vector<pair<int, int>> Q;
cin >> K;
for (int i = 0; i < K; i++)
{
int L, R;
cin >> L >> R;
Q.push_back({L, R});
}
int v = Q[0].l;
++v;
return (K / v) + (K % v == 0 ? 0 : 1);
}
int solve2()
{
int K;
vector<pair<int, int>> Q;
cin >> K;
vector<int> dp(K, 1);
for (int i = 0; i < K; i++)
{
int L, R;
cin >> L >> R;
Q.push_back({L, R});
}
reverse(Q.begin(), Q.end());
for (int i = 0; i < K; i++)
{
int idx = i + 1 + Q[i].first;
if (idx < K)
{
dp[idx] = max(dp[idx], dp[i] + 1);
}
}
// for (int x : dp)
// {
// cout << x << " ";
// }
return *max_element(dp.begin(), dp.end());
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout << solve2();
}
