#include <bits/stdc++.h>
#pragma GCC optimize("O3", "Ofast")
#define int long long
#define ll long long
#define se second
#define fi first
#define pb push_back
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii,pii> ipii;
const int MAXN = 5e5+10;
const int MAXA = 5e4+10;
const int SQRT = 300;
const ll INF = 2e18;
const int MOD = 1e9+7;
const int LOG = 32;
ll sum(auto a, auto b){
ll te = a+MOD+b;
for(; te >= MOD; ) te -= MOD;
return te;
}
void chsum(auto &a, auto b){ a = sum(a,b); }
ll mul(auto a, auto b){ return 1ll*a*b%MOD; }
void chmul(auto &a, auto b){ a = mul(a,b); }
void chmn(auto &a, auto b){ a = min(a, b); }
void chmx(auto &a, auto b){ a = max(a, b); }
ll expo(int a, int b){
if(b==0) return 1;
ll te = expo(a, b/2); te = mul(te,te); // temporary -> te
return (b%2 ? mul(te, a) : te);
}
vector <int> dx = {0, 0, -1, 1};
vector<int> dy = {-1, 1, 0, 0};
int n, dp[MAXN], l[MAXN], r[MAXN];
vector<int> vec[MAXN];
struct seg {
int st[4*MAXN];
int upd(int id,int l,int r,int x,int y){
if(l==r && l==x) return st[id] = y;
if(r<x || x<l) return st[id];
return st[id] = max(upd(lf,l,md,x,y), upd(rg,md+1,r,x,y));
}
int que(int id,int l,int r,int x,int y){
if(x<=l && r<=y) return st[id];
if(r<x || y<l) return 0;
return max(que(lf,l,md,x,y), que(rg,md+1,r,x,y));
}
} A;
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>n;
for(int i=1; i<=n; i++){
cin>>l[i]>>r[i];
}
int ans = 0;
for(int i=1; i<=n; i++){
dp[i] = 1;
for(auto idx : vec[i]){
// cout << idx << ' '<< dp[idx] << " upd\n";
A.upd(1,1,n,idx, dp[idx]);
}
if(1 <= i-l[i]-1) chmx(dp[i], A.upd(1,1,n,1,i-l[i]-1)+1);
chmx(ans, dp[i]);
// cout << i << ' '<< dp[i] << " dp\n";
if(i+r[i]+1 <= n) vec[i+r[i]+1].pb(i);
}
cout << ans << '\n';
}
