#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()
{
int n;
scanf("%lld", &n);
vector<int> a(n + 1), b(n + 1), sweep1[n + 2], sweep2[n + 2];
for (int i = 1; i <= n; i++)
{
scanf("%lld %lld", &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);
int ans = 0;
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);
ans = max(ans, dp[i]);
}
}
printf("%lld\n", ans);
}
