#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define re exit(0);
const int maxn = 500009;
int n;
pair <int,int> p[maxn];
bool given[maxn];
priority_queue <pair <int,int>> pq;
//st
pair <int,int> st1[maxn * 4],st2[maxn * 4];
pair <int,int> merge(pair <int,int> a,pair <int,int> b,int type) {
if (type == 1) {
return (a.first > b.first ? a : b);
} else {
return (a.first < b.first ? a : b);
}
}
void build(int id,int l,int r) {
if (l == r) {
st1[id] = {p[l].first - p[l].second,l};
st2[id] = {p[l].first + p[l].second,l};
return;
}
int mid = (l + r) >> 1;
build(id*2,l,mid);
build(id*2+1,mid+1,r);
st1[id] = merge(st1[id*2],st1[id*2+1],1);
st2[id] = merge(st2[id*2],st2[id*2+1],2);
}
void obliterate(int id,int l,int r,int pos) {
if (l > pos || r < pos) return;
if (l == r) {
st1[id].first = -2e9 - 100;
st2[id].first = 2e9 + 100;
return;
}
int mid = (l + r) >> 1;
obliterate(id*2,l,mid,pos);
obliterate(id*2+1,mid+1,r,pos);
st1[id] = merge(st1[id*2],st1[id*2+1],1);
st2[id] = merge(st2[id*2],st2[id*2+1],2);
}
pair <int,int> get(int id,int l,int r,int u,int v,int type) {
if (l > v || r < u) return (type == 1 ? make_pair(-2e9 - 100,0) : make_pair(2e9 + 100,0));
if (l >= u && r <= v) return (type == 1 ? st1[id] : st2[id]);
int mid = (l + r) >> 1;
return merge(get(id*2,l,mid,u,v,type),get(id*2+1,mid+1,r,u,v,type),type);
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(nullptr);
cin >> n;
for (int i = 1;i <= n;i++) {
cin >> p[i].first >> p[i].second;
}
sort(p + 1,p + 1 + n);
for (int i = 1;i <= n;i++) {
pq.push({p[i].second,i});
}
build(1,1,n);
int res = 0;
while (pq.size()) {
int chosen = pq.top().second;pq.pop();
if (given[chosen]) continue;
res++;
given[chosen] = 1;
obliterate(1,1,n,chosen);
pair <int,int> a = get(1,1,n,1,chosen - 1,1);
while (a.first >= p[chosen].first - p[chosen].second) {
given[a.second] = 1;
obliterate(1,1,n,a.second);
a = get(1,1,n,1,chosen - 1,1);
}
a = get(1,1,n,chosen + 1,n,2);
while (a.first <= p[chosen].first + p[chosen].second) {
given[a.second] = 1;
obliterate(1,1,n,a.second);
a = get(1,1,n,chosen + 1,n,2);
}
}
cout << res;
}
