#include<bits/stdc++.h>
typedef long long ll;
#define pb push_back
#define fr first
#define sc second
using namespace std;
const int inf=2e9+5;
struct Seg{
int n;
bool b;
vector<pair<int,int>>tree,arr;
void build(int node=1,int left=0,int right=-1){
if(right==-1)right=n-1;
if(left==right){
tree[node]=arr[left];
return;
}
const int mid=(left+right)>>1;
build(node*2,left,mid);
build(node*2+1,mid+1,right);
tree[node]=tree[node*2];
if((tree[node]<tree[node*2+1])==b)tree[node]=tree[node*2+1];
}
Seg(vector<pair<int,int>>Arr,bool buyuk){
arr=Arr;
n=arr.size();
tree.resize(n<<2);
b=buyuk;
build();
}
void sil(int tar,int node=1,int left=0,int right=-1){
if(right==-1)right=n-1;
if(left==right){
tree[node]={inf*(b?-1:1),inf*(b?-1:1)};
return;
}
const int mid=(left+right)>>1;
if(tar>mid)sil(tar,node*2+1,mid+1,right);
else sil(tar,node*2,left,mid);
tree[node]=tree[node*2];
if((tree[node]<tree[node*2+1])==b)tree[node]=tree[node*2+1];
}
int l,r;
pair<int,int> qu(int node=1,int left=0,int right=-1){
if(right==-1)right=n-1;
if(left>=l&&right<=r)return tree[node];
if(left>r||right<l)return pair<int,int>{inf*(b?-1:1),inf*(b?-1:1)};
const int mid=(left+right)>>1;
pair<int,int>res=qu(node*2,left,mid),res2=qu(node*2+1,mid+1,right);
if((res<res2)==b)return res2;
return res;
}
pair<int,int> query(int lef,int rig){
l=lef;r=rig;
if(lef>rig)return pair<int,int>{inf*(b?-1:1),inf*(b?-1:1)};
return qu();
}
};
int n;
vector<pair<int,int>>arr,p;
set<pair<int,int>>st;
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);
cin>>n;
arr.resize(n);
for(int i=0;i<n;i++){
cin>>arr[i].fr>>arr[i].sc;
}
sort(arr.begin(),arr.end());
for(int i=0;i<n;i++){
p.pb({arr[i].fr+arr[i].sc,i});
}
Seg mn(p,0);
for(int i=0;i<n;i++){
p[i]={arr[i].fr-arr[i].sc,i};
}
Seg mx(p,1);
for(int i=0;i<n;i++){
st.insert({-arr[i].sc,i});
}
int ans=0;
while(st.size()){
ans++;
int pos=st.begin()->sc;
st.erase(st.begin());
while(true){
pair<int,int>p=mn.query(pos+1,n-1);
if(p.fr>arr[pos].fr+arr[pos].sc)break;
st.erase({-arr[p.sc].sc,p.sc});
mn.sil(p.sc);
}
while(true){
pair<int,int>p=mx.query(0,pos-1);
if(p.fr<arr[pos].fr-arr[pos].sc)break;
st.erase({-arr[p.sc].sc,p.sc});
mx.sil(p.sc);
}
}
cout<<ans;
}
