#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll
typedef pair<int,int> pi;
typedef pair<ll,ll> pill;
typedef vector <int> vi;
typedef vector <pi> vpi;
typedef pair<pi, ll> pii;
typedef set <ll> si;
typedef long double ld;
#define f first
#define s second
#define mp make_pair
#define FOR(i,s,e) for(int i=s;i<=int(e);++i)
#define DEC(i,s,e) for(int i=s;i>=int(e);--i)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lbd(x, y) lower_bound(all(x), y)
#define ubd(x, y) upper_bound(all(x), y)
#define aFOR(i,x) for (auto i: x)
#define mem(x,i) memset(x,i,sizeof x)
#define fast ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define INF (ll)1e18
#define MOD 998244353
typedef pair <vi, int> pvi;
typedef pair <int,pi> ipi;
typedef vector <pii> vpii;
typedef pair <pi,pi> pipi;
#define maxn 500010
int TC;
int N,L[maxn],R[maxn],dp[maxn];
struct node{
int s,e,m,val=0;
node *l,*r;
node(int ss,int ee){
s = ss; e = ee; m = (s + e) / 2;
}
void create(){
if (s != e){
l = new node(s,m); r = new node(m+1,e);
l->create(); r->create();
}
}
int qry(int a,int b){
if (a <= s && e <= b) return val;
else if (a > e || s > b) return 0;
return max(l->qry(a,b), r->qry(a,b));
}
void upd(int p,int v, node *ref){
if (s == e){
val = max(val, v);
return;
}
if (p > m){
l = ref->l;
r = new node(m+1,e);
r->upd(p,v,ref->r);
}else{
r = ref->r;
l = new node(s,m);
l->upd(p,v,ref->l);
}
val = max(l->val, r->val);
}
}*root;
int32_t main(){
fast;
cin >> N;
FOR(i,1,N){
cin >> L[i] >> R[i];
}
vector <node*> roots;
roots.pb(new node(1,N));
roots.back()->create();
int ans = 0;
DEC(i,N,1){
int dp = roots[max(0LL, (int)roots.size() - R[i]-1)]->qry(i,N)+1;
node* nroot = new node(1,N);
nroot->upd(i-L[i]-1,dp , roots.back());
roots.pb(nroot);
ans = max(ans, dp);
}
cout << ans;
}
