#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:x) cout << it << " "; cout << #y << endl;
typedef pair<int,int>pii;
//typedef pair<pii,pii>pi2;
typedef array<int,4>pi2;
inline pi2 combine(pi2 a, pi2 b){
pi2 temp;
//max pos min pos
if(a[0]>=b[0]){
temp[0]=a[0];
temp[1]=a[1];
}
else{
temp[0]=b[0];
temp[1]=b[1];
}
if(a[2]<=b[2]){
temp[2]=a[2];
temp[3]=a[3];
}
else{
temp[2]=b[2];
temp[3]=b[3];
}
return temp;
}
pi2 undo={(int)-1e15,(int)-1,(int)1e15,(int)-1};
struct node{
int s,e,m;
node *l,*r;
pi2 v;
node(int ss, int ee):s(ss),e(ee),m((s+e)>>1),l(NULL),r(NULL){
v=undo;
}
inline void inst(){
if(l==NULL)l=new node(s,m);
if(r==NULL)r=new node(m+1,e);
}
void upd(int x, pi2 y){
if(s==e){
v=y;
return;
}
inst();
if(x<=m)l->upd(x,y);
else r->upd(x,y);
v=combine(l->v,r->v);
}
pi2 query(int x, int y){
if(x<=s&&y>=e) return v;
inst();
if(y<=m)return l->query(x,y);
if(x>m)return r->query(x,y);
return combine(l->query(x,m),r->query(m+1,y));
}
};
void solve(){
int n;
cin >> n;
pii arr[n];
int maxn=1000000005;
node left(0,maxn);
node right(0,maxn);
bool done[n];
memset(done,0,sizeof(done));
map<int,pii>mp;
int cnt=n;
for(int x=0;x<n;x++){
cin >> arr[x].first >> arr[x].second;
if(mp.find(arr[x].first)==mp.end()){
mp[arr[x].first]={arr[x].second,x};
}
else{
if(mp[arr[x].first].first<=arr[x].second){
pii hold=mp[arr[x].first];
done[hold.second]=true;
cnt--;
mp[arr[x].first]={arr[x].second,x};
}
}
}
priority_queue<pii>pq;
for(auto it:mp){
int l=it.first-it.second.first;
int r=it.first+it.second.first;
pq.push({it.second.first,it.second.second});
left.upd(it.first,{l,it.second.second,l,it.second.second});
right.upd(it.first,{r,it.second.second,r,it.second.second});
}
int counter=0;
while(cnt){
pii hold={0,0};
while(!pq.empty()){
hold=pq.top();
pq.pop();
if(!done[hold.second]) break;
}
done[hold.second]=true;
left.upd(arr[hold.second].first,undo);
right.upd(arr[hold.second].first,undo);
int val=arr[hold.second].first-arr[hold.second].second;
cnt--;
while(1){
//left
pi2 hold2=left.query(0,arr[hold.second].first-1);
if(hold2[1]==-1) break;
int index=hold2[1];
if(val>hold2[0]) break;
done[index]=true;
left.upd(arr[index].first,undo);
right.upd(arr[index].first,undo);
cnt--;
}
val=arr[hold.second].first+arr[hold.second].second;
while(1){
//right
pi2 hold2=right.query(arr[hold.second].first+1,maxn);
if(hold2[3]==-1) break;
int index=hold2[3];
if(val<hold2[2]) break;
done[index]=true;
left.upd(arr[index].first,undo);
right.upd(arr[index].first,undo);
cnt--;
}
counter++;
}
cout << counter;
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
//freopen("in.txt", "r", stdin);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
