#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define pb(e) push_back(e)
#define sv(a) sort(a.begin(),a.end())
#define sa(a,n) sort(a,a+n)
#define mp(a,b) make_pair(a,b)
#define vf first
#define vs second
#define ar array
#define all(x) x.begin(),x.end()
const int inf = 0x3f3f3f3f;
const int mod = 1000000007;
const double PI=3.14159265358979323846264338327950288419716939937510582097494459230;
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
bool remender(ll a , ll b){return a%b;}
bool can(int x , int e , int x1 , int e1){
return (abs(x-x1) <= e1-e);
}
bool cmp(pair<int,int> a , pair<int,int> b){
if(a.vs != b.vs)return a.vs > b.vs;
return a.vf < b.vf;
}
void solve(){
int n;
cin >> n;
vector<pair<int,int>> arr(n);
for(int i = 0; i < n; i++)cin >> arr[i].vf >> arr[i].vs;
sort(all(arr),cmp);
set<pair<int,int>> s;
for(int i = 0; i < n; i++){
auto it = s.lower_bound(mp(arr[i].vf,-1));
bool add = 1;
if(it!=s.end()){
int idx = (*it).vs;
if(can(arr[i].vf,arr[i].vs,arr[idx].vf,arr[idx].vs)){
add = 0;
}
}
if(it != s.begin()){
it--;
int idx = (*it).vs;
if(can(arr[i].vf,arr[i].vs,arr[idx].vf,arr[idx].vs)){
add = 0;
}
}
if(add)s.insert(mp(arr[i].vf,i));
}
cout << s.size() << '\n';
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen("deleg.in", "r", stdin);
//freopen("deleg.out", "w", stdout);
//int t;cin >> t;while(t--)
solve();
return 0;
}
