#include <bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); i++)
#define R(i, j, k) for(int i = (j); i >= (k); i--)
#define ll long long
#define sz(a) ((int) a.size())
#define all(a) a.begin(), a.end()
#define vi vector<ll>
#define pb emplace_back
#define me(a, x) memset(a, x, sizeof(a))
#define fst first
#define snd second
#define ii pair<ll, ll>
using namespace std;
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;cin>>n;
vector<pair<int,int>>v;
L(i,0,n-1){
int a,b;cin>>a>>b;
v.pb(b,a);
}
sort(all(v));
reverse(all(v));
vector<bool>vis(n,0);
int ans=1;
vis[0]=1;
L(i,0,n-1){
if(!vis[i]){
ans++;
vis[i]=1;
}
L(j,0,n-1){
if(vis[j])continue;
if(abs(v[i].snd-v[j].snd)<=v[i].fst-v[j].fst){
vis[j]=1;
}
}
}
cout<<ans<<endl;
}
