#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <numeric>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <deque>
#include <fstream>
#include <iterator>
#include <set>
#include <map>
#include <unordered_map>
#include <iomanip>
#include <cctype>
#include <string>
#include <cassert>
#include <set>
#include <bitset>
#include <unordered_set>
#include <numeric>
#define all(a) a.begin(), a.end()
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define pb push_back
#define ppi pair<int,pair<int,int>>
//#define int int64_t
using namespace std;
// /\_/\
// (= ._.)
// / > \>
// encouraging cat
const int INF = 10000000000000000;
//const int mod = 1000000007;
const int mod = 998244353;
const int MAXN = 200005;
//ifstream fin('xor.in');
//ofstream fout('xor.out');
int t[4 * MAXN];
struct Tulip {
int pos, l, r;
};
void build(vector<int> a, int v, int tl, int tr) {
if (tl == tr) {
t[v] = a[tl];
} else {
int tm = (tl + tr) / 2;
build(a, v*2, tl, tm);
build(a, v*2+1, tm+1, tr);
t[v] = max(t[v*2], t[v*2+1]);
}
}
int mx(int v, int tl, int tr, int l, int r) {
if (l < 0 || r < 0)
return 0;
if (l > r)
return 0;
if (l == tl && r == tr) {
return t[v];
}
int tm = (tl + tr) / 2;
return max(mx(v*2, tl, tm, l, min(r, tm)), mx(v*2+1, tm+1, tr, max(l, tm+1), r));
}
void update(int v, int tl, int tr, int pos, int new_val) {
if (tl == tr) {
t[v] = max(new_val, t[v]);
} else {
int tm = (tl + tr) / 2;
if (pos <= tm)
update(v*2, tl, tm, pos, new_val);
else
update(v*2+1, tm+1, tr, pos, new_val);
t[v] = max(t[v*2], t[v*2+1]);
}
}
bool cmp(const Tulip &x, const Tulip &y) {
if (x.r == y.r)
return x.pos > y.pos;
return x.r < y.r;
}
signed main()
{
int n;
cin >> n;
vector<Tulip> tulip(n);
for (int i = 0;i < n;i++)
{
cin >> tulip[i].l >> tulip[i].r;
tulip[i].l = max(i - tulip[i].l, 0);
tulip[i].r = min(i + tulip[i].r, n - 1);
tulip[i].pos = i;
}
sort(all(tulip), cmp);
vector<int> res(n,0);
build(res,1,0,n - 1);
for (int i = 0;i < n;i++)
{
res[i] = mx(1, 0,n - 1, 0, tulip[i].l - 1) + 1;
update(1, 0, n - 1, tulip[i].pos, res[i]);
}
int ans = 0;
for (int i = 0;i < n;i++)
{
ans = max(res[i], ans);
}
cout << ans << '\n';
return 0;
}
