#include <bits/stdc++.h>
#define l first
#define r second
using namespace std;
class SegmentTree
{
public:
int N;
vector<int> tree;
SegmentTree(int n)
{
N = n;
tree = vector<int>(4 * N, 1);
}
int combine(int x, int y)
{
return max(x, y);
}
void insert(int i, int v, int idx = 0, int l = 0, int r = -1)
{
if (r == -1)
r = N - 1;
if (l == r && r == i)
{
tree[idx] = combine(tree[idx], v);
return;
}
if (l <= i && r >= i)
{
tree[idx] = combine(tree[idx], v);
int mid = (l + r) / 2;
insert(i, v, 2 * idx + 1, l, mid);
insert(i, v, 2 * idx + 2, mid + 1, r);
}
}
int query(int w, int l = 0, int r = -1, int idx = 0)
{
if (r == -1)
r = N - 1;
// cout << l << " " << r << " \n";
if (w < l)
{
return 0;
}
if (l == r || r <= w)
return tree[idx];
int mid = (l + r) / 2;
return combine(query(w, l, mid, 2 * idx + 1), query(w, mid + 1, r, 2 * idx + 2));
}
};
int solve4()
{
int K;
vector<pair<int, int>> Q;
cin >> K;
vector<int> dp(K, 1);
vector<vector<pair<int, int>>> queue(K);
for (int i = 0; i < K; i++)
{
int L, R;
cin >> L >> R;
Q.push_back({L, R});
}
SegmentTree ST(K + 1);
for (int i = 1; i < K; i++)
{
for (pair<int, int> q : queue[i])
{
ST.insert(q.second, q.first);
}
dp[i] = max(ST.query(i - Q[i].l - 1) + 1, dp[i]);
int nxt = i + Q[i].r + 1;
if (nxt < K)
queue[nxt].push_back({dp[i], i});
}
// for (int x : dp)
// {
// cout << x << " ";
// }
// cout << "\n";
return *max_element(dp.begin(), dp.end());
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout << solve4();
}
